i did same tests with vmware and low the memory each time[check my posts], the memory used by vista got lower and lower too however below 130MB of memory used its got really slow i think vista used the memory without really need and about 150mb used its enuf to run vista fully http://www.microsoft.com/technet/sysintern...on/bootini.mspx mayb those options could help /BURNMEMORY= • Specifies an amount of memory Windows can't use (similar to the /MAXMEM switch). The value is specified in megabytes. Example: /BURNMEMORY=128 would indicate that Windows can't use 128 MB of the total physical memory on the machine. /MAXMEM= • Limits Windows to ignore (not use) physical memory beyond the amount indicated. The number is interpreted in megabytes. Example: /MAXMEM=32 would limit the system to using the first 32 MB of physical memory even if more were present. go to msconfig>bootini>ad, options