Hi Imre, welcome to the Seven Forums.
A virtual hard disk (vhd) is just a file. If you have deleted the XP Mode's vhd, it should no longer be present "eating" your HD space. After uninstalling Virtual PC and XP Mode, delete all files found in these locations if you are sure you are not going to need anymore:
- C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC
- C:\Program Files\Windows XP Mode
- C:\Program Files\Windows Virtual PC
- (In 64-bit Windows 7, C:\Program Files (x86)\Windows Virtual PC)