For Windows XP:

Step 1: In Windows XP, from Start, and then click on Run.
Step 2: Type “regedit”, then click on OK.

Step 3: Open the Registry Editor.

Step 4: Click on Export Registry.
Step 5: Select All option for backing up every key of registry.
Step 6: Give a destination file (say Regbackup) and save it on to the Desktop.
Step 7: You can easily navigate through the subkey if you know what you are looking for. Or, you can press Ctrl + F to locate the subkey that contains the value you want to edit. (F3 to Find Next)

Step 8: Under this key, there will be the subkeys (some may be absent, which is normal)
Step 9: Click on each Version key to find contents in the right-window pane.
Step 10: Delete all the sub-keys inside.
Step 11: From File menu, click exit.

For Windows Vista:

Step 1: From Start, then type regedit.

Step 2: Click on regedit on the search result to open the registry editor in Windows Vista.
Step 3: Steps are the same as Windows XP (see above).

Now you have been able to remove registry entries from your computer now.