Thanks, Michael York. I have already tried that. As you see in the screenshots the memory consumption when checked through the task manager [Process] is very low ie 9mb to 16mb. But i'm checking it via the physical memory info [performance tab in task man]. I've noticed that during the time of installation, [nw i'm using xp sp2 with dotnetfx3.5sp1] the memory consumption jumps up by 110MB directly. i have the multimonitor bar on desktop and i can see that live. before installation the it would be around 250MB in xpsp2 & while the installation is in progress it jumps to 350-370 and thats permanent no matter what. when idle NIS2009 goes down to 340-350 MB & NIS2010 to 380MB. I' ve ran these tests on clean WINXP SP2 installation with no other softwares installed except my d945gl MB drivers. But of course it shows lite, but monitor the other (check the first page).. any how i'm ok with NIS2009.