Unable to boot XP Media Center

[meinme]

I've HP m7362in PC.
Recently i installed Ubuntu 8.04 in my external Hard disk-120GB Segate FreeAgent Go.
I created 2 partitions in my External Disk (40GB-ext3 and 78GB-Fat32,2GB SWAP). While creating the Fat32 partition i gave the Mount Point as /windows.
During the last step of installation process i chose "Advanced" options and then i chose "install boot loader" to "XP Media Center Edition".
Now i rebooted my PC.
GRUB loaded fine. If i login into Ubuntu, i'm not able to mount any of my Partition other than the Home Folder. i.e. I'm Not able to mount the 80 GB partition as well as my Windows XP Media Center Disk.
In the GRUB, if i choose to boot from XP Media Center, it comes back to the same GRUB page without moving any further.
Now i'm not able to access any of the files in my XP Media Center C: Drive.
Also i'm not able to mount any of those disks.
Please Help me.
I dont have backup for some files in my C: drive and i badly want to access them.
What can i do?

Expecting your reply

[Nico0020]

I have a different system, but a slightly similar problem. I have always been able to access my windows partition, but now it always just returns me to the GRUB menu. I can still access my windows partition from linux though, I can even transfer files between. I checked my grub menu and everything, everything is as it should be. I have not changed anything with my set up, so I am not sure why it stopped working all of a sudden. Anyone know how to get Windows to boot again?

[meinme]

But i'm not able to access my Windows disk even from my Ubuntu. So i'm unable to access any data in it.. Can someone help me retrieve the data atleast!