Caution! I believe this version is for MS Windows XP Pro ONLY! Use it at your risk on Windows 95/98/ME or 2000 computers. The Diskeeper site is very vague with OS information.

Diskeeper® 9 Professional runs on any x86 or equivalent system (including Pentium) running on Microsoft Windows XP Home Edition, Windows XP Media Center, Windows XP Tablet PC, Windows NT 4.0 Workstation, Windows 2000 Professional, Windows XP Professional, Windows XP 64-Bit Edition.

Source:
http://www.execsoft.co.uk/html/smb/dk_sysreq.htm

DISKEEPER 9 PROFESSIONAL EDITION:
Diskeeper® 9 Professional Edition runs on all editions of Windows 95, 98, Me, XP as well as NT 4.0 Workstation and 2000 Professional and will defragment up to 4 drives of up to 512 GB simultaneously.

Source:
http://www.execsoft.co.uk/html/home/dk_sysreq.htm

Does any1 have a backdoor link on Execsoft's retail?

From another forum: When doing an update to v529, I realized that it changes the access permission to a key in the registry and it will prompt error of not being able to open key. To rectify, go to regedit open the key HKLMsoftware. Highlight the Classes key, right click, choose permissions. Go to advance tab and add permissions to full control for Administrators and System. Accept all changes and exit regedit. This applies to those who have simple file sharing disabled and do a backup before proceeding. You could then do a re-install of v524 and then v529 without re-booting. Hope this will help somebody. Tks to lieukeman :-)

From forumtweakxp

Finally, I got a reply from tech support and they're currently working on the problem. According to them, the majority of cases reporting this problem have indicated running some type of registry cleaning utility such as CCleaner or Advanced System Optimizer.

Did you get this version working? I'm still having problems with it.

Yeah. "Registry cleaners" tend to do that over time.
Good program never the less, cheers

thanks

thanks