A useful performance update for Vista:
I had been using Virtual CloneDrive (from Ellaborate Bytes) for sometime with Windows XP and was very happy with it. It allows one to mount .ISO images for CDs/DVDs and use them as a virtual drive.
However I recently realized it was causing slow boot at Windows Vista Ultimate (used "System Parameters" application – try Start/Search to find it at the Start menu – to use "Diagnostic boot" and see how much it takes for each .SYS [device driver] to load) and also slow response of the machine.
Maybe using AVAST antivirus also played a role in it although this combination was seeming to work OK with WinXP (but I might remember wrong cause I remember having some troubles with WinXP [Media Center 2005 in fact] response too before switching for good to Vista Ultimate). Anyway I was using latest AVAST and Virtual CloneDrive s/w.
I used Control Panel’s "Programs and Features" dialog to remove the Virtual CloneDrive application, but it seems VClone.sys kept on loading, so I used Registry Editor’s (regedit.exe) search facility to find "VClone.sys" (search for value) and removed from the registry tree all keys that contained data with that value (were under HKLM\CurrentControlSet, where HKLM=HKEY_LOCAL_MACHINE – similarly HKCU is the shortname for HKEY_CURRENT_USER, with H meaning Registry Hive I think). Also removed under "%ProgramFiles%\Ellaborate Bytes" folder all files related to Virtual CloneDrive
After reboot now the machine seems to work fine and it booted very fast (judging from the Diagnostic Boot trace which prints out each .sys file after it has loaded – in fact all .SYS files seem to load faster than before now – before they loaded more slowly and especially VClone.sys took a long pause before its name was printed [can use Pause key from keyboard to pause the display if it's not slow enough for you to read])