Hi All
Though this post may be a bit late, I can strongly recommend the use of
ERUNT - a very nifty and useful utility that backs up Window's registry as well as an optimizer (NTREGOPT) that compacts and reduces the registry hives - without muckin them up!
I work with Linux too (ISP industry) as well as Windows-based desktops and servers and find that you can clean up your temporary cache easily - you'd be surprised what Windows accumulates in the temporary cache over a short period of time by using
Cleanup.exe - this utility cleans ALL users' temporary caches (unlike CCleaner which does just the user profile you are logged in with) and I agree with the others that CCleaner is very useful with the registry cleanup as well
A suggested methodology would be viz: ERUNT -> Cleanup.exe -> CCleaner (registry part only) -> NTREGOPT (from ERUNT) and you will find the results speak for themselves
A word of caution though - when using Cleanup.exe, set the "Option" to Standard only unless you are brave or know what you are doing
HTH
Cheers
Bill