You can install Firefox to your D:/ drive by selecting a "Custom" installation, but the bulk of Firefox files are going to end up on the C:/ drive in the AppData folder set by default.

You really need to install a larger HDD before installing any additional programs, IMO. Or move your personal data (images especially) to the D:/ drive to free up space on the C:/ drive.

Problem is it's an office computer, not my personal computer, and a new drive is unfortunately out of the question. So far I've deleted everything I can find that's not necessary, from the C drive.

There are three XP service packs and I'm wondering if the first two can be deleted as unneeded as they are real space hogs. Still trying to get an answer to that question.

Thanks for Your help

Note that the Firefox profile folder takes considerably more space than the Firefox program folder.
The disk cache can be up to 384 MB and there are more large files.

• http://kb.mozillazine.org/Moving_your_profile_folder
• http://kb.mozillazine.org/browser.cache.disk.parent_directory

You need both SP1 and SP2 to be able to run Firefox.
http://www.mozilla.org/en-US/firefox/23.0/system-requirements/
And getting rid of SP3 probably isn't wise from a security standpoint.

Have you looked through your "data" to see what can be moved over to the D:/ drive? Also you should consider moving the Windows TEMP files over to the D:/ drive.

Also, with WinXP it is a good idea having at least 15% of each logical drive "free" so that the Defrag service can be run; TEMP files cause the most fragmentation on the drive.