As I noted in a earlier post I have switched to using Server 2008 as my main OS and configured it so that I can boot with or without the Hypervisor enabled.

Today I got round to installing SP2 and after the machine came back up it felt sluggish, as though the Hypervisor was enabled which is odd as my default boot configuration has it disabled.

A quick check of my boot config showed that the service pack had reset 'hypervisorlaunchtype' to 'Auto' for all entries

Very annoying but easliy fixed...

The other issue I've had is that the SP install removed 'Windows Mail' from my quick launch bar. Also annoying but easliy fixed.

Like a bunch of folks I have moved over to running 64-bit Windows Server 2008 as the primary OS on my laptop, a Dell D830.

The only problems I've had so far are that when the hypervisor is active sound playback is very poor and graphics performance becomes very poor - resizing a window is very jerky and takes ages. VM performance is great but the host seems to suffer. If you use Virtual PC/Server you'll notice that their performance is awful when the hypervisor is active.

I recently found the solution in this blog post http://blogs.msdn.com/virtual_pc_guy/archive/2008/04/14/creating-a-no-hypervisor-boot-entry.aspx.

You need to create an alternate boot configuration woth the hypervisor loaded. It's a simple fix -

1. Start an administrative command prompt
2. bcdedit /copy {current} /d "Microsoft Windows Server 2008 - no hypervisor"
3. bcdedit /set {identifier for the new boot entry (copy from the output of a plain 'bcdedit' command)} hypervisorlaunchtype off

and next time you boot you can choose to have the hypervisor on or off.