Is it ok to delete everything in my C:WINDOWSTEMP folder? What about any other *.tmp files lying around?

Files in the WINDOWSTEMP directory and files with the extension *.tmp are usually temporary files which are no longer needed by Windows, or a particular program, but the program which was using them didn’t delete these temporary files. It should be ok to delete all the files in the TEMP folder. You may get some errors when deleting some of the files as they may still be in use. If you do, then don’t delete the files for which the errors are appearing. With regard to the other *.tmp files lying around, it should be safe to delete these but I suggest that you leave them in the recycle bin for a couple of days just in case they are needed by an application (in which case you can restore the file(s)).