unable to start other operating systems

Details as requesed maile to
<email address hidden>

Was GRUB able to detect WindowsXP during startup at least?

   Gerät boot. Anfang Ende Blöcke Id System
/dev/hda1 191 1649 11719417+ 1c Verst. W95 FAT32 (LBA)
/dev/hda2 1650 2432 6289447+ f W95 Erw. (LBA)
/dev/hda3 * 1 58 465853+ 6 FAT16
/dev/hda4 59 190 1060258+ 6 FAT16
/dev/hda5 * 1650 2395 5992213+ 83 Linux
/dev/hda6 2396 2432 297171 82 Linux Swap / Solaris

Yes, GRUB knows about Windows. I can select DOS or Windows or Ubuntu from the first menu. Selecting DOS will boot to DOS. This situation is shown on above partition table where DOS resides on hda3.
If I select Windows, the second screen tells me:
"Booting Microsoft Windows XP Home Edition
root (hd0,0)
filesystem type is fat, partition type 0x1c
save default
makeactive
chainloader +1"
Then the system hangs forever.
That means to me that the function 'makeactive' does not activate the partition of the selected OS.
In a next step I forced the Windows partition (hda1) into the active state (with 'Partition Magic'). Selecting again Windows from the first menu still freezes the system. However, after restarting Ubuntu, the partition table shows the effect of altering the active partition:
The boot asterisk has moved to hda1 and the "1" in the Id column (indicating 'hidden') has moved to hda3.

To summarise:
1. Ubuntu (makeactive) does not activate the partition of the selected OS.
2. Forcing the DOS partition into the active state enables booting to DOS.
3. Forcing the Windows partition into the active state still does not allow to boot Windows.

Can you gain access to your windows install from the recovery console by booting to your xp disk? If not, it sounds like your windows partition is corrupted.

If you can, then consider fixmbr at the recovery console prompt. This will replace your master boot record allowing you to boot into windows. Keep in mind that you will no longer have access to DOS or Ubuntu after that.

The next step would then be to reinstall grub and configure it to see all three partitions.

HTH

Did you add any new partitions to your drive when you installed Ubuntu? if you already had a partitioned system, say part1, part2, part3 and you installed XP on part1 then proceeded to install on part2 and part3, then that's an okay scenario and something else must be wrong. If, for example you initially only had part1 with XP in it then added new partitions, then Windows might not have been able to boot because of these changes.

Actually, it's just something that I encountered with Windows 2000 (not XP, I know but it might be related). I had FC3 and Windows 2000 running fine on that machine. Then I decided to remove FC3 and install Debian on it but this time with less partitions with the initial FC3 install. Windows 2000 was instantly broken. I had to repartition the drive to let it have the same number of partitions that it had before I removed FC.

I have erased everything and started installation of Windows and Linux from scratch. Thanks to everybody for contributions.
Peter