Dear all, I didn't get any reply, so I send this mail again. On one of my windows Vms (KVM), I get from time to time a 'windows recovered from a serious error' message, and if I click the wonderfully useful (ahum) support link, I reach this page: http://wer.microsoft.com/responses/Response.aspx/1445/en/5.1.2600.2.00010... I quote the first part of it here: "Consider BIOS upgrade Microsoft is unable to determine the exact cause of this error. However, this problem was most likely caused by an error in your computer’s random access memory (RAM). RAM is the main internal storage area the computer uses to run programs and store data. During the crash analysis, we noticed the basic input/output system (BIOS) version on this computer does not match the specifications for the central processing unit (CPU), also known as a processor, that is installed on your computer. This can occur when a newer processor is installed on an older system board or older BIOS. Using a BIOS that does not support the installed processor can result in Windows system crashes. Contact your computer manufacturer or motherboard manufacturer for an updated version of BIOS for your computer's processor." Now I'm not sure what this is all about: how can I possibly upgrade my VM's BIOS, or should I do something else? Can it have something to do with the processor specs in the VM's XML definition? Thanks for looking into this, Jürgen