Taking data from old HD with left over user security

Thanks for taking the time to read this question.

Here's the situation:

I have an older hard-drive that I finished installing into my new machine. However, before I took the old machine apart I did not remove my user account. I've tried to boot directly from the drive in order to log in via the old installation of windows but it failed. (old brain in new machine problems). My old hard-drive has my old collection of music and instead of having to re-download the files I'd like to just grab them off the old drive. When I try to access the folder my music was in it says "access denied." Unfortunately I cannot rebuild the old machine as the parts are at home (im a college student) so I'm stuck with what I've got. I'm 100% sure the hard-drive works as I'm able to access all the other programs I had installed, I just can't get to my old user files (music, school assignments, etc.)

My question:

Is it possible to (since I know the password) to get access to that folder without having to rebuild the old machine?

Some things I've considered trying, but would like feedback first....

Reinstall windows on the old drive while disabling the HDs I currently use.

Any help would be greatly appreciated.

-Matt