My friend has a dell desktop running windows XP home edition she purchased in 2003. I installed a webcam for her and I noticed how slow her pc was and the system was hanging up in between programs. The next day when I went back to troubleshoot the pc I received the blue screen and the error message unmountable_boot_volume

I restarted the pc and keep getting the same error message.

Does this sound like a hard drive error?
Thank you.