I have owned a Toshiba Satellite L505d laptop running windows 7 for almost 3 years now. Before heading off to college I have been clearing out files and backing them up onto external hard drive. I noticed my computer had used 225gb of the allotted 250gb on my hard drive, but i couldn't find the culprit of what was taking up all that space. I had emptied out the folders i use for image and video files. Program files only accounted for about 25 gb, but when i checked a folder called ATI (assuming the drivers of the video card on my pc) it accounted for 200gb of space. I'm no expert but how could that possibly be? Is it safe to delete this data?
I would assume that it would be safe to delete because the only C:\ATI folder that I know of is made by ATI's install program for temporarily holding file during driver install.
However, 200GB?! That's quite some number of driver updates, given monthly updates for 3 years and aprox. 150Mb per update, accounts for 5400MB. That doesn't come close to the size of your ATI folder. Fishy.
Run WinDirStat on it and see what folders and files take up the space. You should be able to delete the ATI folder completely if it doesn't have any of your personal data files. Next time an update comes out it will re-create the ATI folder and unpack the new driver there.