why can't I dual boot after I installed Ubuntu 12.04
 

I installed Ubuntu 12.04 and was able to dual boot with no issues. Then I mad the mistake of missing with the partition label. when I tried to restart my computer it said error unknown system file. I was able to use the Ubuntu live CD to download boot repair. Now I have my windows XP OS working fine, but i can't dual boot. I delete Ubuntu 12.04 and reinstalled but still can not dual boot. Is there someway to fix this. Yesterday was the first time in terminal, so if the solution is through that I will need step by step direction for dummies. Thank you in advance.

Not sure what you mean by "messing with the partition LABEL", but if you run the LiveCD and open Gparted, it will tell you what is currently present on your hard drive. From there you may be able to figure out what happened. Give it a try.

I opened Gparted and the hard drive had every thing still on it, so I ran boot repair again, every things working now. I was talking about the partition letter not label.