Updating Windows 7 build instructions.
Updating Windows 7 build instructions.

jackwadden/VASim,jackwadden/VASim,Jinglei-Cheng-THU/VASim,Jinglei-Cheng-THU/VASim,jackwadden/VASim,Jinglei-Cheng-THU/VASim,Jinglei-Cheng-THU/VASim,jackwadden/VASim