>I have a very old PC with a small (9 GB) hard drive. This drive is getting so full a new XP Service Pack wouldn't install because there wasn't enough space. I've added a decent size (80 GB) second drive (F:) and managed to free up enough space on the primary drive to install the SP.
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>The drive is still so full that some programs won't install and I'd like to free up some significant space.
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>The Windows directory is well over 4 GB. There's another 1.5 GB in Program Files.
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>Asssuming that there is a great deal of stuff that can safely be removed, I've made complete copies on the new drive. Now I need some help on the next steps.
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>1. What type of file can I safely delete from the C drive. I'm thinking of LOG, CAB, JAR. Are any of these safe to delete? Are there any others?
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>2. I've set TEMP and TMP environment variables for my user profile to point to F:\tmpfiles. There are also system variables of the same name which point to the C drive. Is it safe to assume that my user profile overrides the system variables?
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>3. What would be the effect of taking the system variables Windir and Winbootdir, both of which point to C:\Windows, and making them point to F:\Windows. Would that mean I no longer need the directories on the C drive?
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>Any other suggestions (junking the machine is not an option at the moment) are welcome

The best option is almost certainly to "ghost" (copy) the partition on the small HD to the new one, then ditch the old one entirely. You can also choose to expand the size of the copied partition to include more, or all, of the new drive so the copied partition is larger than it was before.

Products such as Norton Ghost and Acronis True Image can do this. There are also free/open source tools such as PartImage, NTFSClone and QtPartEd/GPartEd on various Linux live CDs such as Knoppix.

One issue you may run into is if the computer is really old, its BIOS may not recognize the full 80GB size of the new drive. Actually, if you've already installed it as a secondary drive you should already know if it recognizes the whole drive by now. It should recognize at least 32GB of the drive, which would still be a huge improvement over 9GB.