This is a really annoying problem and may affect others out there. I have two new XP Pro machines with dual core processors which have some large backup files and virtual PC files. When I run the windows defragmenter or any defragmenter for that matter when large files are being processed particularly towards the end of a move of a file XP or usually Windows Explorer stops responding until the move has completed. I cannot access start menu, task manager or programs that are already running while the move of the large files is under way. I have run the defragmenter in safe mode and this doesn't seem to happen. I have used MSconfig to start under diagnostic conditions and could not reproduce the problem but I seemed to lose some of my startup items so had to restore from a backup. The two computers are different hardware but have similar software configs. Please help regards Tim1 person got this answerI do too

Sorry to bump this but has no expert any idea or could test to see if it's a common xp problem or just my config?

Well I have increased my motherboards ram to 4gb and the problem seems less obtuse with just a slight freeze or nothing at all when defragmenting large files. I understand the Windows API moves files in 1gb chunks while using defragmenter so maybe there just wasn't adequate memory and xp was paging. Not entirely sure it's fixed but it seems so, so I have increased the ram in my other machine to 4gb too. I know only 3.25 is usable but maybe the extra 1gb makes the difference?