DiGuru said:Yes, that was the first thing I tried. It helped, but not by much. I suspected that Windows thought it was a system file of some kind. But it is definitely the fault of the build-in defragger. It is a big file (2.6 GB), so if the defragger doesn't try to make free space continious, it just doesn't fit. And it didn't even try to defrag it.
Like I said before, use Contig from Sysinternals. It's the absolutely best tool for this kind of problem. Depending on the fragmentation of your hard disk it might not be able to fully defragment the file, but it will decrease the fragment count considerably, most probably to 100 fragments or less (your mileage may vary).
A good strategy is to defrag your hard disk with the built-in defragmentation utility, then use Contig on any file that still has more than 100-200 fragments and then use the built-in defragmentation utility again.