Hi dessos
First, let's try to get your machine to boot XP again. Unless someone has a better suggestion,
Boot the Tinycore CD
Plug in a USB thumbdrive
Click on the Mount icon and mount the thumb drive
Open a terminal and enter:
dd if=/dev/sda of=xpmbr.bin bs=512 count=1
Copy the file xpmbr.bin to the thumb drive as a backup for now.
Click on the Apps icon and install ms-sys.tcz and gparted.tcz
In the terminal, enter:
ms-sys -m /dev/sda
This assumes that sda is your windows drive, please verify first.
Now click on the gparted icon and verify that the Windows partition boot flag is set
Assuming I haven't made any errors, that should restore the MBR and allow Windows to boot again. You may want
to wait before trying this to see if any other forum members can offer any comments.