Hey Guys, I installed Windows 7 x64 today and when i opened the system information tool, it shows 3.25GB usable. So, i checked with task manager and it shows the same 3326(3.25) to my surprise. How is this possible on a x64 OS? Memory mapping is on 32 bit if i am not wrong... Have been using Vista x64 for the last 1 year or more and never faced this issue and was able to use full 4GB RAM, so no BIOS issue. If i go to Msconfig > Boot > advanced option > Maximum memory > change it to 4088 from 4096 or any other value and restart, The RAM is detected now as 3.25GB. This was not the case with Vista x64. If i leave it unchecked, 4GB RAM is again detected and used properly. This is an issue for those having Hauppage PVR-150 and planning to move to Windows 7 x64, since this hardware like many others needs a change of usable RAM to 4088 which could be set here and then the tuner card worked...(This used to work in Vista x64) But now, with this bug, Maximum Memory option does not work properly in Windows 7 as it used to in Vista. So, Hauppage PVR-150 just won't work in Windows 7 x64 anymore... Guys, if anybody has a workaround, plz help.