Today, I went on a computer of mine, going into My Computers and some of it's folders. Then, I pressed the "Hidden Files" button, hoping to get rid of unwanted Temporary Files. After what seem like forever loading, some of the icons of the desktop were gone! Can someone help me?

Do a Gurgle search for "Software to restore Desktop" There are some useful articles in the Microsoft Knowledgebase.
YOu might want to run a Repair install of your windows disc, if it will do it.

I'm not sure where you were to click on Hidden Files and I surely don't know why you thought this was a way to 'get rid of temporary files' so let's break it down:

To "view" Hidden Files and Folders:
Control Panel> Folder Options> View Tab> check 'show hidden files and folders'.
The main reason these are hidden is to prevent the user from deleting needed files. Neither temporary internet files nor temp files are hidden (with the exception of some Cookies)

To delete temporary internet files:
My Computer> Right click on Local Drive- usually C> Properties> Disc Cleanup

To additionally delete these files:
Control Panel> Internet options> General tab> delete temporary internet files> delete History> delete some or all of the Cookies.

Having said all of the above which you need to do, I highly recommend that you do NOT 'show hidden files and folders'! Do a System Restore to date before you deleted files. If you're lucky, they may still be in the Recycle Bin!

Control Panel> All Programs> Accessories> System Tools> System Restore> check 'restore my computer to an earlier time'> next> choose a date in BOLD on the left before you deleted the files> next> let the process continue. The computer will reboot when finished. Hopefully you will have you icons back!