Skillset: reverse engineering, software cracking.
[url removed, login to view] contains routines FileLock and FileLockEx
As far as I know, they are responsible for file locks in Windows
Your job is to modify these routines so that when they are called they do not create any locks
If anything else creates the locks I don't know: your job is to disable windows file locking
The result being that no file can be locked by any process
Do this for Windows XP and Windows 7. Or give price for only one if you prefer.