Opening Visio Problem

[jcreek]

I have several Visio programs with some irreplaceable data in them.
Problem: When I try to open a program a
"box opens which says that the program is open in another application
Please close & try again" I click OK
then a second box appears and says "Visio internal error #3400
action 1283: open file
first try closing & reopening the file
next try restarting Visio
OK"


I have closed and even restarted computer but the same boxes keep coming back.
Not real computer good so please show all the details you can.

Thanks for any help
Rod