Actually, this is a supported method by Microsoft, but you have to know what you are doing. The standard caveat about modifying the registry applies. In, fact the link DEBeast has in his orginal post points to an MS Article describing this exact registry hack. I have used it many times after ghosting a partition. This only works if your system was orginally installed as C: and somehow the drive letter got changed. This appears to be tha case for DeBeast and is why I suggested this solution. This will cause major problems if your system installed as some drive letter other than C:.
