How do I

....Hi all! I'm new here and I know very little about my 27 " Imac. It has been awesome but has slowed right down and is telling me to remove files from my startup disk? What is this and how do I do this?

Welcome to the Mac Forums.

How full is your hard drive? Open the Finder, click on or highlight the item that says "MacIntosh HD", and then look at the bottom of the dialog and see how much space you have left. Post that back here.

The message you're seeing may be telling you that the hard drive is filling up and there is not enough space. What were you doing when you received that message?

Also when you post back it would be helpful if you gave us some specs: Year, model of your machine, and which version of OS X you're running. Memory and size of the hard drive.

Woooo boy Dont delete ANYTHING from the start up disk. You could do more harm than good.
Oh and welcome to M-F

First goto disk utility via Applications>Utilities folder and click you HD in the left column. Then make sure the First Aid tab is highlighted and perform a Repair Permissions of that HD. Once dome log out then back in and see if you have a change of speed.
Once done report back if its no change. Then someone else can have a go as im off to work

HTH

Cheers

EDIT : Do what Charlie said 1st ^^^^ Always forget the Full HD thing lol

Here is the specs.... 1TB hard drive w 937 gig available I5 less than 1 year old. running Aperture and the print shop 2 thats about all!

Photoguy said:

Here is the specs.... 1TB hard drive w 937 gig available I5 less than 1 year old. running Aperture and the print shop 2 thats about all!

Click to expand...

In that case do what i suggested in the above post or dl MainMenu 1.7.4 (dont update it s this is free and will update you to the paid version) and run the scripts in Batch Tasks. Configure it 1st to uncheck Spotlight Reindexing and Remove .DS_Store Files. Make sure everything else is checked then run it.

It will do a better job than Disk Utility and cleans up your Machine from junk and get rid of corrupt file/folders

Cheers

If you have a 1 TB hard drive with 937 GB remaining of free space you should not be getting a message to remove files from your startup disk.

I suggest doing a verify of your hard drive before anything else. Boot your machine with your original Snow Leopard DVD (hold down C key right after you hear the chime and keep holding it until you see the apple).

Do not allow the install process to continue, instead click on the top menu item that says "Utilities", then click on "Disk Utility". Next, select the First Aid tab on the right side and further select the Verify and Repair option.

Let us know what it says.

Edit: Try what Tattoo suggested first.

How much RAM do you have installed? You need a bunch to get Aperture to run at all smoothly.