I am helping a friend who uses T-Bird on a Windows 7 PC that had a hard drive crash. Installed T-Bird 24 on another PC that works on Vista and it initially worked fine. In attempting to drop files from old to new, after a reboot, I try to open T-Bird and get a message that t could not open as another version of T-bird was in use (nothing visible). After several attempts to delete and re-install, here I am.

Any help