virtualbox.org

When I start virtual machine I get an error



Host: Windows 7 x64
Guest: Windows 7/Vista x64

How to fix it?

tekken,

I believe that this question has been asked about 104 times now.
You need to download and install the drivers from realtek.com and then tell Windows to update.
Also a read of the Forum Posting Guide would help you.
Searching the forum from google.com using sound problems in window 7 site:forums.virtualbox.org will bring up a lot.

Sorry about that
I installed guest additions so I thought I do not need to install another drivers.
My sound device on host is fine on vista guest too but I still get this error at the start of virtual machine.

No problem just remember this trick. Use your keywords in google followed by site:forums.virtualbox.org.
It will become your best friend!

I reinstalled host, then guest, installed realtek drivers and still the same error. Is it a hardware problem? I have sound on both os, it is strange.

In the guest settings: Enabled Nested Paging and Enable PAE/NX if they are not already and see if this helps.

It seems work now
But sometimes there is GUI crash during shutting off and wrong cpu speed show in system properties

This could be caused by the way Windows 7 RC is calling things and also that SMP is so new to VirtualBox.
You may want to wait a little and see what happens once Windows is officially released, but play with it and see if you can pin it down a bit and then get back to us.

OK, I'll wait till Win7 RTM release. I find VirtualBox 3.x very useful.