Hi all, I have the following PC: CPU - Intel Core i3 530 MB - Gigabyte H55M-S2H GPU - Nvidia Geforce 9400 GT RAM - (old) 1x2gb Kingston hyperx DDR3 1600 MHz / (new) 2x4gb Kingston hyperx DDR3 1600 MHz and the problem...... I had 32bit win7 with 1x2gb, and i installed the new kit, 2x4 gb..... BIOS recognises all 8gb, windows says I have 8gb but only 3,5gb usable (because of 32 bit system). all good until here if i want to reinstall windows (either 32 or 64) with the new 2x4gb RAM, windows installer freezes at the "starting windows" screen. So i can only install (both) windows with the old 1x2gb RAM. Now i installed windows 64 bit with the old set of 1x2gb RAM, and when i change the RAM to the new 2x4gb it wont boot, also stops at the "starting windows" screen..... So i reinstalled the windows 32 bit, and i can see 8 gb (3,5gb usable).... That is the best config I can make out of this PC....... my goal would be 64bit with 8gb RAM Oh and I tried windows 7 and windows 10 versions......both 32/64bit Can anyone here help me?