I am in serious need to update my computer.

There have been close to 100 iMac variants made since 2006 wheh Snow Leopard was released. Some early iMacs cannot run any higher OS than Snow Leopard. That's why Kappy posted teh system requirements for Lion. To start, tell us what processor your have byt doing "About this Mac" from your Apple menu (left end of menubar). You should get this:

Note that one of the items I highlighted is processor information. What does your Mac show for that entry?

The iMac sub-model is also important. IN OS 10..6.8 finind it is a bit indirect but y ucan do it from that "About this Mac" window. Click the "More Info..." button to launch System Profiler. Its opening screen looks like this:

Again I used a red arrow to highlight the important bit. On your computer, what code shows in the second line? Also post how much memory is installed. With that we should be ale to more precisely advise you on your upgrade options.

Basic Steps for Upgrading OS X

Upgrading to Lion

You can purchase Lion at the Online Apple Store. The cost is $19.99 (as it was before) plus tax. It's a download. You will get an email containing a redemption code that you then use at the Mac App Store to download Lion. Save a copy of that installer to your Downloads folder because the installer deletes itself at the end of the installation.

Lion System Requirements

1. Mac computer with an Intel Core 2 Duo, Core i3, Core i5, Core i7,

or Xeon processor

2. 2GB of memory

3. OS X v10.6.6 or later (v10.6.8 recommended)

4. 7GB of available space

5. Some features require an Apple ID; terms apply.

Are my applications compatible? See App Compatibility Table - RoaringApps.

Downloads like this one should be stored in your computer's Downloads folder which is located in the Home folder.

Within your Purchases at online Mac App Store, items such as the Lion 10.7

upgrade should appear, so if you needed to get it more than once from there,

you need not have paid again. Also, be sure to use DiskMakerX or another

method to make an offline copy of Lion 10.7 or later download installers due

to the fact that once you run them, they disappear from the Application folder.

Depending on the build year and model version iMac, you may be able to go

as far as El Capitan 10.11.6 from Snow Leopard 10.6.8. ~ If so, that's free.

And upgrade requirements always suggest, where possible, to upgrade hardware.

This could mean more chip memory RAM, &/or larger capacity storage hard drive;

some require special effort if replacing a hard disk drive due to sensor issues.

{Not all older version Intel-based Mac can make the leap to macOS Sierra.}

Yours may/not make the grade: Upgrade to OS X El Capitan - Apple Support

Memory upgrade RAM chips of best quality are highly recommended, such as

those from crucial.com site, or from reputable vendor OWC macsales. They

have specific parts for each build model series, and have been tested in them.

Good luck & happy computing! 🙂

Before embarking on a major OS upgrade, it would be wise, advisable and very prudent if you have a good, working backup of your current system to an external connected and Mac formatted Flash drive OR externally connected USB, Thunderbolt or FireWire 800, Mac formatted hard drive. Then, use either OS X Time Machine app to backup your entire system to the external drive OR purchase, install and use a data cloning app, like CarbonCopyCloner or SuperDuper, to make an exact and bootable copy (clone) of your entire Mac's internal hard drive. This step is really needed in case something goes wrong with the install of the new OS or you simply do not like the new OS, you have a very easy way/procedure to return your Mac to its former working state.

Then, determine if your Mac meets ALL minimum system install requirements.

OS X 10.7 Lion system requirements

Purchased emailed download code here.

http://store.apple.com/us/product/D6106Z/A/os-x-lion

Apple will send you an email for the special download code for the Mac App Store within three days of purchasing the download code.

To use OS X 10.7 Lion, make sure your computer has the following:

An Intel Core 2 Duo, Core i3, Core i5, Core i7, or Xeon processor

Mac OS X v10.6.6 or later to install via the Mac App Store (v10.6.8 recommended)

7 GB of available disk space

2 GB of RAM

To download and install either the pay OS X 10.8.5 Mountain Lion or the free macOS Sierra OR OS X 10.11.5 El Capitán you need one of these Macs:

OS X 10.8 Mountain Lion purchased emailed download code here.

http://store.apple.com/us/product/D6377Z/A/os-x-mountain-lion

Apple will send you an email for the special download code for the Mac App Store, for OS X 10.8.5 Mountain Lion within three days of purchasing the download code.

For Mac OS X 10.8 Mountain Lion through OS X 10.11 El Capitán.

iMac (Mid-2007 or later)

MacBook (13-inch Aluminum, Late 2008), (13-inch, Early 2009 or later)

MacBook Pro (13-inch, Mid-2009 or later),

MacBook Pro (15-inch or 17-inch, Mid/Late 2007 or later)

MacBook Air (Late 2008 or later)

Mac mini (Early 2009 or later)

Mac Pro (Early 2008 or later)

Xserve (Early 2009)

Your Mac also needs:

OS X Mountain Lion, Lion, or Snow Leopard v10.6.8 already installed

2 GB or more of memory (I strongly advise, at least, 4 GBs of RAM or more)

8 GB or more of available space

For upgrading to macOS Sierra, you need to meet these minimum Mac system hardware requirements.

MacBook (Late 2009 or newer)

MacBook Pro (Mid 2010 or newer)

MacBook Air (Late 2010 or newer)

Mac mini (Mid 2010 or newer)

iMac (Late 2009 or newer)

Mac Pro (Mid 2010 or newer)

These Mac hardware models need to be running OS X 10.7.5 Lion or later OS X version to upgrade and install macOS Sierra.

Next,

If you run any older Mac software from the earlier PowerPC Macs, then none of this software will work with the newer OS X versions (10.7 and onward). OS X Snow Leopard had a magical and invisible PowerPC emulation application, called Rosetta, that worked seamlessly in the background that still allowed older PowerPC coded software to still operate in a Intel CPU Mac.

The use of Rosetta ended with OS X Snow Leopard as the Rosetta application was licensed to Apple, from a software company called Transitive, which got bought out, I believe, by IBM and Appe could no longer secure their rights to continue to use Rosetta in later versions of OS X.

So, you would need to check to see if you have software on your Mac that maybe older than, say, 2006 or older.

Also, check for app compatibilty here.

http://roaringapps.com/

If you have any commercial antivirus installed and/or hard drive cleaning apps installed on your Mac, like MacKeeper, CleanMyMac, TuneUpMyMac, MacCleanse, etc. now would be a good time to completely uninstall these apps by doing a Google search to learn how to properly uninstall these types of apps.

These types of apps will only cause your Mac issues later after the install of the new OS X version and you will have to completely uninstall these types of apps later.

Once you have determined all of this, you should be able to find the latest versions of OS X by clicking on the Mac App Store icon in the OS X Dock and then login to the Mac App Store using your Apple ID and password and if you purchased a download code, input that code.

You can then begin the download and installation process of installing the newer versions of OS X from the Mac App Store.

Good Luck!

Some 2006 iMac models cannot upgrade their Mac OS past OS X 10.6.8 Snow Leopard.

A 2006 iMac is now approaching 12 years old, now.

It maybe time for you to upgrade your Mac to something new or "newer" (used).

OS X 10.6.8 Snow Leopard is going to be a 9 year old operating system.

I was a former OS X Snow Leopard " hang-er on-er" and saw the "handwriting on the wall" and moved past Snow Leopard over two years, ago.

There is only one recent secure web browser left for OS X Snow Leopard and even that has stopped support for OS X Snow Leopard the past May 2017.

If your iMac is an 8.1 model, that is a 2008 iMac.

You need, at least, 2 Gbs of RAM to install OS X 10.7 Lion.

That year and model iMac can take up to 6 GBs of RAM and can either run OS X 10.7.5 Lion, 10.8.5 Mountain Lion OR the free OS X 10.11 El Capitán.

You MUST use THE EXACT RAM that your model iMac is spec'd for.

Correct and reliable Mac RAM can ONLY be purchased from online Mac RAM sources Crucial memory (crucial .com) or OWC, aka, Other World Computing (macsales.com).

When buying RAM for Macs from Crucial memory, purchase ONLY directly from the Crucial memory website. NOT from some other online source.

OWC is THE only source for the 6 GBs of RAM.

RAM in iMacs is, relatively easy to install.

https://eshop.macsales.com/item/Other%20World%20Computing/6400DDR2S6GP/

https://eshop.macsales.com/installvideos/imac_mid_2007_mem/

Good Luck!

If needing to run older software is an issue, forget installing OS X 10.7.5 Lion and pay for the download code and go straight to OS X 10.8.5 Mountain Lion instead.

It's much better than OS X 10.7 Lion and should still run all of your older software.

Either way, if you decide to install and run an older OS X version, be advised that you will need to run a more secure web browser as the versions of Safari that come with OS X 10.7 and 10.8 are hopelessly out of date and completely unsecure.

With OS X 10.7 Lion the last compatible web browser is Mozilla FireFox ESR 45.9.

Firefox 45.9 ESR .dmg install file here.

https://ftp.mozilla.org/pub/firefox/releases/45.9.0esr/mac/en-US/

Dbl click to download, locate the Firefox 45.9 ESR.dmg on your Mac.

Dbl click on the file and it should put up both a disk drive looking image and a pop up installation window.

Drag the Firefox Application icon into the Application folder shortcut icon in the same install window.

The go to your Applications folder, find Firefox, the launch it!

You may need to update Adobe Flash Player to the last compatible version for Firefox 45.9

You need to use Adobe's Flash Player uninstaller, first, to uninstall the older Adobe Flash Player.

https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html

On the Adobe Flash Player section of the Adobe website, you will need to look for the last Adobe Flash Player version compatible with Mozilla Firefox 45.9.

This is the Adobe Flash Player you are looking for on the Adobe web site.

Adobe Shockwave Flash version 26.0.0.137

Look toward the bottom half of this webpage link.

https://fpdownload.macromedia.com/pub/flashplayer/installers/archive/fp_26.0.0.1 31_archive.zip

Once downloaded on your Mac, dbl-click to open the zIp file

Dbl click to Install the Mac OS version if there is one listed in the archive file (might be a .dmg file).

When you open that Adobe Flash Player archive file, it will create an archive folder.

Dbl click that folder, two other folders will appear.

Click the first folder WITHOUT THE words debug in it!

When that folder opens you are looking for a Mac OS .dmg file with this name

flashplayer26_0r0_131_mac.dmg

Dbl click on this and begin the install procedure from the brownish red Adobe install folder that appears.

For OS X 10.8.5 Mountain Lion, the ONLY compatible and very recent and up to date web browser is Waterfox.

Waterfox is based on the most current, up to date versions of the Mozilla Firefox web browser.

https://www.waterfoxproject.org/

With this only supported and current, up to date web browser for OS X 10.8.5 Mountain Lion, you can install the most current version of Adobe Flash Player.

Good Luck to You!

You are in luck. I have the same iMac and it runs El Capitan fine.

You do not need to buy any software to upgrade to OS X El Capitan (10.11)

You do need to upgrade your ram to at least 4GB. This should be bought from OWC Macsales, easy to buy online and easy to upgrade following videos from their site.

From 10.6.8 you can download and upgrade to 10.11.6 on Apple's site for free.

El Cap is a modern OS and you can do just about anything that a new computer can do, just a little slower.

Good luck.

OP can upgrade to the free OS 10.11 El Capitan only if the OP has software that is compatible with it OR can afford to upgrade/update older software.

Some users using older OS X versions, like myself, need to stay with older OS X versions to continue to use older, sometimes expensive, legacy software that some users, like myself, can no longer afford to upgrade to newer, more compatible versions.

Some regular contributors here, who constantly recommend updating to the latest Mac OS for best security reasons, sometimes fail to take those kind of considerations and circumstances into account.

MichaelPM,

I see your point. I guess you are assuming that OP is using Photoshop and does not want to upgrade. I'm surprised that photoshop would run well in 10.6 with 1gb ram. Perhaps he is not using Photoshop?

Psalgie,

If you are using Photoshop you will see a significant increase in productivity by upgrading ram to the max, even with 10.6.

Still, if that's the case I really don't see much point in upgrading from one obsolete os to another obsolete os. Might just as well stay in 10.6. where his photo programs, whatever they are, are running well.

If on the other hand you want a modern os that works on the internet and with modern software it is amazing that a ten plus year old computer can run 10.11 and run it fairly well (better with an SSD).

With OS X 10.8, and later OS X versions, you get the benefit of using a current, up to date, secure web browser.

Plus, I am talking about ANY apps that may cost more money to upgrade/update.

Audio apps.

Video apps.

Office/productivity apps.

Other types of drawing/sketching apps.

Other page layout apps.

Engineering/CAD apps,

Etcetera, etcetera, etcetera, ad nauseum...

Other photography/image editing apps. There are other paid apps other than just Photoshop.

Not just Adobe apps.

Most users don't have scads of cash to spend on updating bunches of apps that are no longer compatible with newer Mac OSes.

I am very happy continuing to use OS X 10.8.5 AND OS X 10.9.5 with current, up to date versions of Waterfox and Mozilla Firefox.

Think McFly...

Yes

In one word. (well 7 now)

With only 1Gig I would say it's time to cut your losses and buy a new Mac...