Well actually, it didn't work.

After going through the steps on that website, I loaded Windows 7 first. I saw both Win 7 and XP in the system boot. After that, I tried to load XP and it showed me this:
Code:
Windows failed to start. A recent hardware or software change might be the cause.
Here is where it tells me how to repair the computer.
File: \ntldr
Status: 0xc000000F
Info: Application missing or corrupt.
After that I tried going through the steps again using the command prompt on Win 7. It still didn't work.
Then I used the Win 7 disk and used the command prompt on that. When I try to load XP it still gives me that error message.