I built myself a computer a couple of years ago and run it now with Ubuntu 9.04 under Xen 3.0. I'm not a hardware expert by any means, but I managed to make it all work. However, due to the lack of support for Xen by Ubuntu, I can't easily upgrade to more recent versions of the operating system. I have therefore decided to switch from Xen to KVM, which is supported by Ubuntu.
My current CPU, an Intel Pentium 4 Processor 640, is not KVM-compatible (i.e. does not provide VT-x or AMD-V). My motherboard is an ASUS P5LD2. I have looked for other processors which work with the ASUS P5LD2 motherboard, implement VT-x or AMD-V, and are available in shops near me.
The Intel E6700 seems to fit the bill.
If I switch off my computer, replace the Intel 640 with an Intel E6700, update the BIOS for the E6700, and switch it back on again: will it still work with the existing installed software (Xen 3.0, Ubuntu 9.04 etc.)? Or do I have to reinstall everything from scratch?