Below I have a "short list" of files perfectly safe to delete. This short list will still save a considerable amount of hardrive space. Some XP users may feel a little more comfortable following this list as a guideline rather than the master list above. The master list I use is pretty extreme, and is geared more to the advanced, "fearless", computer user.
Just like you would do before you apply any major change to your system...backup. It is so very important to backup our systems regularly. Believe it or not, technically, I haven't re-installed XP in over a year's time.
I do a lot of tweaking and deleting tests, and sometimes I need to re-install...but I only have to re-install XP, and then immediately install the Drive Image program so I can get to a backup image I have saved, either on another partition, or on a 700MB CD. So I never have to "start from scratch", so to speak.
I have numerous backup images on 700MB CDs...dating back to over a year ago. All I have to do is pop one in, copy it to another partition, and use it to restore my system to a different place in time.
That is actually the main reason I delete files. I do need the extra space for this backup method. I have to have my stored backup images each below 700MB. (That's the "compressed backup image" Drive Image makes, not the actual size of the installation on disk. You need to use my master list above to downsize to that point.) The more programs I install, the more disk space is taken up, and more the need to delete some files to save space.
Although this is a short list it is still too long to post here, so I have it here.
http://www.bit-quest.com/forums/index.php?showtopic=1697&st=30
Scroll to the bottom of the page.