I have been using VM WS7 for more than a month, and for that had upgraded RAM from 5gb 1333 to 7 gb 1333 gb. Initially, it was fast (VM machine of win 7 64 bit with around 3 GB RAM) allocated. However, lately I have been finding some slowness esp. in startup and opening folders. Could be because of the recent VM ws7 update but could it be because shared (host) folders are enabled by default, mapped as network, and accessing host folders/files may be taking some time. Kindly help me about this. Will a RAM allocation increase to around 4 GB help. Use only VM machine at a time. Regarding the 10 tips, I do not usually follow full screen mode (sometimes do), disable CD (can do so but would rather not), split VHD (machine already built), disable windows visual effects. Do defrag regularly with PD pro and RAM and cpu seems adequate. Also will increasing the cores per machine help. Have a core i7-920 processor and as noted, at a time, only 2 machines are running-host and guest.