Mani
I delve in the registry at least 5 days a week since 1997 & do a lot of
programming using the registry etc. too.
Many uninstall programs leave registry keys instact or partially deleted
(leaving the top-level key there)
My advice is don't bother restoring it to a previous state because not only
does it hold info on your installed apps, but if you have an application you
have not needed to install, but have run the chances are that there are
registry keys referrring to that & then you have lost that type of info too.
Example: All 'System Interals' (now Microsoft) apps that you run add info to
the registry & so does HijackThis, but that also adds itself to the
add/remove program list too
So, you see you would be constantly restoring your registry if you do that.
However, you could edit the registry yourself & keep the
HKEY_CURRENT_USER\SOFTWARE & HKEY_LOCAL_MACHINE\SOFTWARE clean of redundant
keys 'IF' you know what you are doing, but forget it if you don't
Hope this helps,