Hi I think I can help you with this question but first of all I need to know which operating system you are using?
Till then you can do one thing. select the "start menu" and then choose "run" option. after that a dialog box will appear, there you have to type "%temp%". then press "ok". then a folder will appear, then you delete everything in that folder. some of the programs will give warning before deleted, don't delete those program those are very essential for your computer to run. and others are useless junk. after that some you'll get some free space in a particular drive where your operating system is installed.
reply me after trying.
deleting the contents of the hidden temp folder wont be just the only thing...
go: my computer - (saying the drive with teh operating system on is C) C:Windows\Temp
youll notice that all temp files (including the files in jongsons folder) are more than likely 0 in size and deleting them will free up around 30kb...
delete all programms do dont use anymore: start - control panel - programs and features.. XP Add or Remove Programs
delete all your temp internet programs.. ctrl+shift+delete
open computer/mycomputer and right click your drive - select properties and under the general tab click 'disk cleanup' selects everything and delete the lot..
now click teh 'tools' tab and select 'defragment now' and let your hdd defrag.. but be warned you could be sitting there for hours waiting for the defrag to finish
normally when your computer is starting, you can continuously either hit F10 or F11 until you get a screen that asks you if you want to reconfigure your computer..from there its pretty self explanatory. im assuming you dont want to back up what you have on it now on a disk, so when you are asked if you want to go back and back it up, hit no...its different with every computer, but I hope this helps! I just did this to my HP laptop so I know it works