this is my system:
- Windows 7 on an SSD
- Ubuntu Server on a SATA hard drive
I need to remove Ubuntu Server and install Ubuntu Desktop, without causing a fuss.
the difference between ubuntu server and desktop is primarily the kernel. Install the ubuntu desktop metapackage (or kubuntu... or) if you want a GUI. If you really want, install the 'regular' kernel and uninstall the server kernel. Reboot.