Hello Randy,
If you reformatted the hard disk all the RT files are gone. You need to make your PXI be a dual boot. You should use a boot disk. Here is a
Link on how to do it.
Now another important thing that is mentioned in that link is that your system should be FAT32. When you are installing Windows XP in a FAT32 system (which you had before, since you had RT)it asks you sometime if you want to convert it to NTFS.
If you did this, then you will need to convert it back to FAT32.
This is not an easy process, but it is explained in more detail in the same link.
Hope this helps you.
Ricardo S.
National Instruments