I tried to install Windows 7 RC x86 several times. Every time I tried to do it, my computer froze at the very beginning of the process, still running from the DVD like here: http://windows7forums.com/windows-7-installation-upgrade/5131-windows-7-crash-install-bsod-stop-0-00000124-a.html The moment of freezing is the same, however the stop errors (BSODs) are not. I get IRQL NOT LESS OR EQUAL most of the time. I got 000000d1, then 0000007e, then 000000d1 with an additional line saying netio.sys froze. Then I pressed F8 during install, and tried to install it in safe mode. It froze with "Page Fault Found In A Non Paged Area" and stop code 00000050 three times. The last line that was shown on screen before freezing was disk.sys all three times. I have a perfectly functioning installation of Vista Business on another partition. (I have perfectly functioning installations of XP Pro and Ubuntu on the second hard drive.) Then I tried to run the installer from Vista, choosing a clean install on another (NTFS-formatted and empty) partition. The first stage of file copying was completed, at the first restart however, where Windows 7 RC created a dual-boot menu for the old Vista and for itself with the name "Windows Setup" it froze exactly as before, immediately after showing the Starting Windows screen. This time the stop error (BSOD) message was 0000008e. I tried twice more, the same thing happened. I have an nForce 4 Ultra-based Asus A8N-SLI Deluxe main board with an AMD Athlon 64 X2 3800+ (2000Mhz) Toledo S939, Gigabyte ATI Radeon X550 128MB and 4 identical sticks of 1024 MB Kingmax DDR 400Mhz RAM (which can only run at 400 Mhz if I stick in at most two of them. If I insert more than two modules, and I try to run them at 400 Mhz there will be freezes every few minutes, so currently I use them at 333Mhz without problems. That means that a Memtest86 full test completes without error at 333Mhz with 4 GB RAM) Freezing 15 times out of 15 with a stop error on a machine that runs Vista perfectly is serious. I know that the nForce 4 chipset has loads of bugs, especially with the SATA controller and its buggy AHCI and hot swap capabilites. NForce4 chipset mainboards do not have any BIOS option to enable the AHCI mode of the nForce S-ATA ports. There is simply no such option in BIOS. What could be the problem? Help me, please.