Primary or Slave

Today i had a new hard drive installed at Best Buy. I formatted/partitioned it. Booted windows xp fron cdr and installed on drive. Now when i try to start computer i get an error that only says, "error loading OS_"

When i tried to reboot i pressed F1 and got the BIOS screen.
It has the drives listed as:

Primary [none]
Slave [wd120gb]
Secondary [cdrom/dvd combo]
secondary slave [cdrom]

Does this mean that they installed the new drive as a slave and this is the problem? Or did i goof it up installing windows?
Once i put the cdr in and it started i just followed the directions, really it only said take out disk 1 insert disk 2 etc.. everything seemed to install fine.