Two weeks ago when I rebooted our Win2008 R2 Server (64-bit) it started to power up and load Windows (Windows 2008 Server) but would then suddenly turn-off and start powering up again (and then just keep suddenly turning off, restart, repeat).
I tried booting into safe mode and last known configuration - no joy. It was falling over on classpnp.sys. So I thought I might have corruption on the disk and tried to repair the server from the CD and then I was able to restore the O/S from a backup. I thought that was the end of it but then the next time the server rebooted I had the same problem. Then trying to repair from CD did not work.
I tried repartitioning the disk and installing Windows 7 instead but the installation did not even complete before the PC was powering off mid-boot. I contacted the hardware supplier and they thought it might be the RAM so they've sent me 3 replacement DIMMs, I've swapped those out and the PC isn't powering off anymore but...
The server was trying to boot from the incomplete Windows 7 install. I took the disk out and deleted the 2 volumes on that disk and now trying to install Win2008 from CD. I get the black screen:
Windows is Loading files ...
that completes, and then the grey screen appears with a cursor, but no window/dialog (I'm expecting it to prompt me what language and keyboard I want to use). The server just sits there. alt+tab, ctrl-alt-del, etc. don't have any effect.
If I try booting with no CD I get
BOOTMGR is missing
How do I get past that grey screen? Or is this a hardware failure?
Sounds like you have a hard drive failing or some other kind of hardware. Can you swap drives and test again?