ADD 11 Home - Volumen change not working (German/Deutsch)

Dear all, (Hallo alle, hoffe es ist auch jemand der deutsch kann hier ist)

yesterday I start the firsttime to work with ADD 11 Home. I get it new, install and look who it works.

I have XP Pro, and one HDD (250 GB) with 2 Partions. First c:/ with 20 GB and my OS (XP Pro), and the other GB on a other Drive x:/. Now I have online 4-5 GB free on C:/, so ein want to change the volume-size from the other (x:/) to get a bigger C:/ Drive (I also have another separat HDD)

Both Partitions are Basic and Primär (primary). The OS HDD is Drive 2 with c:/ and x./, and the other HDD Drive 1. Now I want to change the size, make the partions of x:/ smaller, and make c:/ bigger. I press with the right mouse on the x:/ and choose "Volumen-Size-Change". I takge 20 GB. All values on the screen i don´t change. Then I start the action. The PC ist getting down to make the change.

The PC ist booting to make the ADD-change. After few seconds I get a ADD Error Screen.

Fehler (german for Error)
Code 00360191 .....
Suberror:
Text: Fdisk-Aktion fehlgeschlagen (means Fdisk-Action Mistake)
And now some Suberror Codes, and last a "Invalid file reference"
The screen end with the Information that a could press enter for restart.

Could somebody help me?
Best Regards
Vito