I guess there are already threads dedicated to this subject - which files and folders you can safely delete from a Windows XP partition without having any problem. Unfortunately I cant'd find them ...

AVG Anti-Virus 8 Anti-Virus 8 is a free antivirus program that is compatible with various Windows systems, including Windows 2000, Windows XP, Windows XP Pro x64, Windows Vista, and Windows Vista x64.

Warnings While removing a drive letter for a network drive or virtual drive doesn't delete any files, it may cause errors in applications that try to retrieve a file using the deleted drive letter.

How to delete a file being used by another program Here are some practical ways to dodge the pop-up and delete files that are in use by a program on your Windows PC.