Windows Registry contains a lot of orphaned and superfluous information after a few months of usage: recently used files for many apps, not more existing SharedDlls, etc - which is cleaned by many registry cleaning tools.
Yet I've seen no tool to care about:
- Orphaned HKEY_CLASSES_ROOT\Interface records
sometimes there may exist a lot - check an AHK script to enumerate and delete them
- Explorer ShellTray notification icons arrangement
as much as 3MB is quite usual :-) check it yourself, run: regedit /e c:\test.reg HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\TrayNotify
then see the size of c:\test.reg file and divide it in two. See the next item for a cure.
- Explorer wallpapers recently used list
mine was 0.5MB, check it by running: regedit /e c:\test.reg HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Wallpaper
here's the reg to clean shelltray and wallpapers MRU list. Paste to notepad and save it to "CleanRegTrayAndWallpapers.reg", type it with quotes(!), then double click it and perform a Windows re-login.
After all these clean-ups the Registry contains a lot of interspersed blocks marked as free, which is not good since new data won't necessarily fit in any of those. So a defragmentation is required, here's IMHO the simplest and fastest tool to do it: One Click Windows Registry Optimizer, 140kb portable version (no installation is required)