My Mac is unusable

"Two days ago I was writing up a doc on word and a message came up saying my start up disc was almost full"

This is why it lags, and why it failed to boot. Liion requires 7 GB of free space to boot and subsequently run. You need to free up disk space.

Where did my Disk Space go?

Why is my computer slow?

You should never, EVER let a conputer hard drive get completely full, EVER!

With Macs and OS X, you shouldn't let the hard drive get below 15 GBs or less of free data space.

If it does, it's time for some hard drive housecleaning.

Follow some of my tips for cleaning out, deleting and archiving data from your Mac's internal hard drive.

Have you emptied your iMac's Trash icon in the Dock?

If you use iPhoto, iPhoto has its own trash that needs to be emptied, also.

If you store images in other locations other than iPhoto, then you will have to weed through these to determine what to archive and what to delete.

If you use Apple Mail app, Apple Mail also has its own trash area that needs to be emptied, too!

Delete any old or no longer needed emails and/or archive to disc, flash drives or external hard drive, older emails you want to save.

Other things you can do to gain space.

Once you have around 15 GBs regained, do a search, download and install OmniDisk Sweeper.

This app will help you locate files that you can move/archive and/or delete from your system.

STAY AWAY FROM DELETING ANY FILES FROM OS X SYSTEM FOLDER!

Look through your Documents folder and delete any type of old useless type files like "Read Me" type files.

Again, archive to disc, flash drives, ext. hard drives or delete any old documents you no longer use or immediately need.

Look in your Applications folder, if you have applications you haven't used in a long time, if the app doesn't have a dedicated uninstaller, then you can simply drag it into the OS X Trash icon. IF the application has an uninstaller app, then use it to completely delete the app from your Mac.

Download an app called OnyX for your version of OS X.

When you install and launch it, let it do its initial automatic tests, then go to the cleaning and maintenance tabs and run the maintenance tabs that let OnyX clean out all web browser cache files, web browser histories, system cache files, delete old error log files.

Typically, iTunes and iPhoto libraries are the biggest users of HD space.

move these files/data off of your internal drive to the external hard drive and deleted off of the internal hard drive.

If you have any other large folders of personal data or projects, these should be archived or moved, also, to the optical discs, flash drives or external hard drive and then either archived to disc and/or deleted off your internal hard drive.

Good Luck!

🙂

Also, how much RAM installed in your iMac?

Yeah, never let your disk get full and how much RAM do you have?

MichelIPM solution is always more RAM and belittling you.

You could try a an NVRAM/PRAM reset

1. Shut down your Mac.
2. Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.

After resetting NVRAM or PRAM, you may need to reconfigure your settings for speaker volume, screen resolution, startup disk selection, and time zone data.

If this doesn't help, you could try an SMC reset

1. Shut down the computer.
2. Unplug the computer's power cord.
3. Wait fifteen seconds.
4. Attach the computer's power cord.
5. Wait five seconds, then press the power button to turn on the computer.

Good Luck!

BTW,

The late 2009, 21 and 27 inch screen iMacs originally shipped with 4 GBs of RAM.

If you are running OS X 10.6 Snow Leopard, this should be sufficient amount of RAM

To find out info about your system,

click on the Apple symbol in the upper left of the OS X main menu bar.

A drop down menu appears.

Click About this Mac.

A smaller popup window appears.

This gives you basic info like what version of OS X your iMac is running, the speed of your iMac's CPU and how much RAM is installed.

Click on the button that says More Info.

A larger window appears giving you a complete overview of your iMac's hardware specs. Highlight all of this info and copy/paste all of this into another reply to this post, editing out your iMac's serial number before actually posting the reply. This will tell us everything about your iMac.

If your iMac is telling you that you only have 2 GBs of RAM, then one of the RAM modules could have failed or needs to be reseated in its RAM slot or it is simply missing the extra RAM.

Your iMac year and model can take a total of 16 GBs of RAM.

Correct and reliable Mac RAM can be purchased from online Mac RAM sources Crucial memory or OWC (macsales.com).

You need to clear out your drive space. This is the underlying issue. No RAM upgrade will be of any benefit until this is resolved.

I agree!

😉

If you can't get your system to login or boot to the Finder or your iMac freezes once you get to the Finder, the only other option is to purchase and connect an external FireWire 400/800 or USB 2 hard drive and if you have a retail OS X install disc, you can quit the Installer app, launch OS X disc's Disk Utility app and format the new external hard drive as an OS X extended (jounaled) format with a GUID partition scheme. Then, relaunch the Installer app and continue to Install OS X onto an external drive and then boot your system into the external drive.

From there, you can access your iMac's internal hard drive and begin the process of copying data to external hard drive and thinning out/deleting data from your iMac's internal hard drive bringing your iMac back to a usuable state.

Good Luck!

Well,

If all you have gained is 24 GBs of RAM, while this is better, it's really is still NOT a lot of free hard drive space.

It won't be long until you, again, reach that 10-15 Gb free space range and you'll be back to where you started.

You need to purchase that external hard drive.

Personally, I recommend a fast, external FireWire 800 drive with its own dedicated power. Not a laptop style external hard drive. If you rather go cheap, you can choose just a USB 2.0 ext. drive, just get one with its own dedicated power supply.

And downgrading from LIon to Snow Leopard requires and complete erase, reformat of your iMac's internal hard drive and reinstall of OS X Snow Leopard from disc.

There is no other alternatives.

So, you will need that external hard drive anyway to perform a backup of all of your important, personal data.

In additon, 2 GBs of RAM is not going to cut it on OS X Snow Leopard, either.

This is a bare mimumm RAM requirement.

I do not know why your iMac model didn't ship with the standard 4 GBs of RAM, but you need, at least, this much RAM installed to run OS X Snow Leopard.

Your iMac model can take a total of 16 GBs if RAM max.

My advice, purchase and install (2) 4 GB RAM modules for a total of 8 GBs of RAM.

This will be enough RAM for your needs.

Correct and reliable Mac RAM can be purchased from online Mac RAM sources Crucial memory or OWC (macsales.com).

As for downgrading from OS X Mountain Lion/Lion to OS X Snow Leopard, here's a well outlined procedure from another user discussion from long-time forum contributor and Mac user, Kappy.

https://discussions.apple.com/thread/5240711?start=0&tstart=0

You will need your orignal OS X Snow Leopard disc or Snow Leopard on a system restore disc, that comes with your iMac, to do the downgrade.

Good Luck!