Removing Hidden Partition from factory?

Hi,

I have an Acer Laptop Aspire, I am very happy with it, it's an old one from 2006 or 2007.
It's working fine, I am using a dual Boot System with XP and Windows7.

One harddisk. At the start of this DISK there is a Hidden Partition from Acer itself with drivers and other stuff to restore the system. Of course I don't use this. There is 4 Gb on it and I will remove this partition. I only want my XP and Windows 7 partition on it but I don't know how to do that.

In the past I've tried this but I don't succeed and the system won't start anymore. After that the only thing I could do was using the recovery disk to restore the whole disk which I backupped on a NAS.

Maybe I have to change something in the BootMgr file because there are references where these partitions begin on the disk??? Or something like that?

Is there anybody who can help me with this complicated issue?

Thanks!
Luvene