i do use diskeeper professional premier edition it works well and it also supports boot time defrag and automatic defrag features which i lik the most and moreover the defragmention is very fast:hap2:
I am surprised to see that no one uses Perfect Disk, since it is widely considered to be the most thorough one. It does a wonderfull job. O&O is pretty average stuff, nothing special. I dont know how the latest diskeeper does though. Didnt feel like downloading 30+mb. I tried its previous versions and found PD to be better.
Try perfect disk guys. Its not a huge download either.
I used Perfectdisk for years in XP - but last year it started troubling me so I changed top Diskeeper. For Vista I use a freeware defragger Auslogics Disk Defrag - I think I saw this on the current CHIP or Digit CD/DVD