I'm unable to delete old Streets & Trips maps saved earlier in My Documents

I want to delete some old maps that I saved earlier in My Documents, but I can't get rid of them.
Any suggestion on how to delete them?
I have Streets & Trips 2009 and Windows XP.

Did you try to delete them with window explorer while S&T is closed?

If it is not working, it is possible that you got a crash in S&T while using these files so they are locked. Reboot your computer, don't run S&T and delete these files in window explorer...