Good morning Michael and welcome to CH
I know what Dusty is talking about but Windows 7 doesn't use the boot.ini XP does use the boot.ini
If you can still boot into windows 7 it is very easy to change.
When you are at the W7 desktop First, you’ll need to right click on Computer and select Properties Next, click Advanced System Settings Now click on the Settings button under Startup and Recovery And just select the operating system you want to use.
That's it you are all set, hopefully this helps. Mike