I am new to Linux. I recently installed Ubuntu Desktop 11.10 onto my portable hard drive. Much to my surprise, it installed half of GRUB to the PC, and half to the PHDD. The PC does not belong to me. GRUB got removed from the PC, but that's not the issue. I want to be able to boot Ubuntu from my PHDD on any PC. I share one Windows XP PC with my family, but the BIOS is locked and I cannot change the boot order, so I installed PLoP and added it to the Windows boot menu. I don't want to need the boot disc to boot. I just want to be able to have Ubuntu boot when I boot from the external drive. I am not installing anything or changing anything on a PC. I don't want GRUB on my PC. I cannot open up my PC and remove the internal HDD. I cannot boot Ubuntu from my PHDD as it is. All I want is truly portable Ubuntu. If there is a way to have some kind of bootloader that only needs to be on the portable HDD, maybe one that works with PLoP, it would be much appreciated. I may have to add more details later. Thank you.
To restore the original (probably Windows) bootloader onto the PC: