Virtual machine

[aldo_albanese-/E1597aS9LQAvxtiuMwx3w at public.gmane.org (aldo albanese)]

Not sure if this is the right audience but you have been knowledgeable about 
other stuff as well.

I have been using VM Oracle VirtualBox.  I heard other people using Microsoft 
Virtual Machine desktop.  I was wondering which virtual desktop you like best 
and why.  The main OS is Windows 7. 

On a different note, I know I already mentioned before but I could not find a 
definitive answer on this post or other Goggle searches on why after installing 
Ubuntu 10.10, I  could see Windows XP but after updating it, Windows XP is not 
showing up anymore.  Since I'm new to Linux, I was wondering if you know how to 
change it to to add Windows XP back.

Thanks,
Aldo