XP crash after changing cpu cores, and after reverting

[PeppeJ]

So I changed my cpu cores on my Windows XP VM and tried starting it, this casued it to crash everytime on the "welcome" screen so I reverted the setting back to a single core. Now it keeps crashing just like I mentioned unless I hit F8 during boot and "Load Last Known Good Configuration" where as it will always work. Does anyone know what might cause this and/or how it can be solved?

[Perryg]

If you set up the guest as a single processor and then change it to a multi processor you must change the guests kernel to support that. Windows is none to friendly about that but it can be done.

This is going to require VT-x and it being enabled as well as IO/APIC

You can try this and see if it helps. http://forums.virtualbox.org/viewtopic. ... 52#p122752
HALu is the part you are looking for.
Be sure to keep a backup of the VDI