Error code 0x000000C4 for Fedora20 host trying to run Win7 64x guest on VirtualBox 4.3

[J Freyensee]

In running Virtualbox on an HP Elitebook 840 w/8GB RAM running 64-bit Fedora 20, I get the following error when I try to run a 64-bit .iso of Windows 7 64-bit for the first time:

Your PC needs to restart. Please hold down the power key Error Code: 0x000000C4 Parameters: 0x00000...000091 (lots of zeros)

0x00000...00 (all zeros)

I've attached the log and .png

[J Freyensee]

Note this seems to be a similar problem that was reported for Ubuntu host running Win7 64-bit client about 6 months ago:

https://www.virtualbox.org/ticket/12744

Only downgrading to VirtualBox 4.2 (which did work as a workaround for that bug) does NOT fix the problem.

[J Freyensee]

It appears that this workaround I found doing some Internet searching:

VBoxManage setextradata [your vm name] VBoxInternal/CPUM/CMPXCHG16B 1

Does seem to work. I got the Win7 64-bit .iso to boot for the very first time.

I do not consider that a fix to get a win7 64-bit .iso to boot in VirtualBox 4.3 for the first time though.

[Frank Mehnert]

Interesting finding. Please could you provide the exact version number of Windows 7 you are trying to install? As far as I know, the cmpxchg16b instruction is only required on Windows 8.1 / 64-bit.

[Frank Mehnert]

Actually your screenshot clearly shows that you are NOT installing Windows 7. This is most likely Windows 8.1. Just set the OS type properly ("Windows 8.1 (64-bit)") and it will work properly.