need help upgrading

If it's an IntelMac, 10.6 would be cheaper.

Leopard requirements/10.5.x...

* Mac computer with an Intel, PowerPC G5, or PowerPC G4 (867MHz or faster) processor

minimum system requirements

* 512MB of memory (I say 1.5GB for PPC at least, 2-3GB minimum for IntelMacs)

* DVD drive for installation

* 9GB of available disk space (I say 30GB at least)

Classic/OS9 Apps no longer supported.

Trouble is Apple no longer sells it, check eBay & such for the Retail version, not the Gray Discs...

http://www.ebay.com/sch/i.html?_nkw=mac+os+x+leopard+retail+10.5

Snow Leopard/10.6.x Requirements...

General requirements

* Mac computer with an Intel processor

* 1GB of memory (I say 4GB at least, more if you can afford it)

* 5GB of available disk space (I say 30GB at least)

* DVD drive for installation

* Some features require a compatible Internet service provider; fees may apply.

* Some features require Apple’s MobileMe service; fees and terms apply.

Which apps work with Mac OS X 10.6?...

http://snowleopard.wikidot.com/

Call Apple Sales...in the US: 1-800-MY-APPLE. Or Support... 1-800-275-2273

Other countries...

http://support.apple.com/kb/HE57

It looks like they might still have it...

http://store.apple.com/us/product/MC573Z/A?fnode=MTY1NDAzOA

About Safari 5.1.7 and Leopard Security Update 2012-003

Summary

Learn about Safari 5.1.7 and Leopard Security Update 2012-003.

Products Affected

Mac OS X 10.5, Product Security, Safari 5.1 (Mac OS X 10.6), Safari 5.1 (OS X Lion)

Safari 5.1.7 for OS X Lion, Safari 5.1.7 for OS X Snow Leopard, and Leopard Security Update 2012-003 disable out-of-date versions of Adobe Flash Player.

Out-of-date versions of Adobe Flash Player do not include the latest security updates and will be disabled to help keep your Mac secure. If Safari 5.1.7 or Leopard Security Update 2012-003 detects an out-of-date version of Flash Player on your system, you will see a dialog informing you that Flash Player has been disabled. The dialog provides the option to go directly to Adobe's website, where you can download and install an updated version of Flash Player.

Additional Information

If you need to re-enable an out-of-date version of Flash Player, you can do the following:

1. Navigate to the /Library/Internet Plug-Ins (Disabled) folder.

2. Drag "Flash Player.plugin" into /Library/Internet Plug-Ins.

3. If the browser is running, quit and restart it.

http://support.apple.com/kb/HT5271

http://support.apple.com/kb/HT5655

10.5.8 is the final version of Leopard. To get later versions of Safari than 5.0.6 you have to upgrade your operating system. If yours is a PPC (G4 or G5) Mac you cannot. If it is Intel based:

Start by checking if you can run Snow Leopard:

Requirements for OS X 10.6 'Snow Leopard'

http://support.apple.com/kb/SP575

(NB: PowerPC applications can still be run in Snow Leopard using Rosetta, but they will not work in later versions of OS X. For detailed information see this user tip: https://discussions.apple.com/docs/DOC-6271 )

The OS 10.6 Snow Leopard install DVD is still available for $19.99 from the Apple Store:

http://store.apple.com/us/product/MC573/mac-os-x-106-snow-leopard

and in the UK:

http://store.apple.com/uk/product/MC573/mac-os-x-106-snow-leopard

Before installation you should back up all your data.

When you have installed it, run Software Update to download and install the latest updates for Snow Leopard to bring it up to 10.6.8, or download the combo update from here:

http://support.apple.com/kb/DL1399

Check via Software Update whether any further updates are required, particularly to iTunes (you will need the latest version in order to synch with mobile devices).

You should now see the App Store icon in iTunes, and you now need to set up your account:

http://support.apple.com/kb/HT4479

You can now upgrade to Mavericks OS 10.9 for free IF you have one of the following Macs, with not less than 2GB of RAM, and at least 8GB of available space on your hard drive:

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

iCloud system requirements:

http://support.apple.com/kb/ht4759

If you cannot run Mavericks you can purchase the code to use to download Lion from the App Store (Lion requires an Intel-based Mac with a Core 2 Duo, i3, i5, i7 or Xeon processor and 2GB of RAM, running the latest version of Snow Leopard):

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

or Mountain Lion:

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

At the Apple Icon at top left>About this Mac, then click on More Info, then click on Hardware> and report this upto but not including the Serial#...

Hardware Overview:

Model Name: iMac

Model Identifier: iMac7,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.4 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 4 MB

Memory: 6 GB

Bus Speed: 800 MHz

Boot ROM Version: IM71.007A.B03

SMC Version (system): 1.21f4

Yes,

http://www.everymac.com/systems/apple/imac/specs/imac-core-2-duo-2.16-20-inch-sp ecs.html

RAM...

http://eshop.macsales.com/MyOWC/Upgrades.cfm?sort=pop&model=256&type=Memory

Install Videos...

http://eshop.macsales.com/installvideos/imac_intel_white_mem/

And, even though yours can do 10.7.5 I can't recommend it, I'd stick with 10.6.8

OK, good luck! 🙂