By Hmm; Norton Speed Disk caused havoc with my PC yesterday.
It ended up not booting and I had to take the drastic step of reinstalling. Took a grand total of 7 hours to get my PC back to the state it was prior to the problem; with the exception that I eventually need to reinstall all my games.
Damn, I hate Norton...
I've never used Norton Speed Disk, well not recently anyway, I used to use the DOS version many many years ago. I don't bother with any of the Norton stuff now, there was a time when I loved it but it all seems too bloated and invasive now, and I wouldn't fancy installing System Works or Utilities just to defrag my drive.
When I was deciding which defragger to use under Win2K Pro (and now XP), I just played it safe and chose Diskeeper Pro, as the standard Windows Disk Defragmenter is just a very trimmed-down version of that product. The fact it was considered reliable enough to be included with Win2K was good enough for me, and it hasn't given me any problems.