Excel Problem

[TheeOx]

Greetings all,
I have a co-worker who is pulling various amounts of hair out of her head over this problem:
In Excel, when she has a certain workbook(s) open, she cannot open any other workbooks.
This problem happens once in awhile, but is quite a pain in her heiny.
I have an idea what the prob is, but wanted help from the pros in this forum.

Any suggestions?
Thanks,
Love,
Thee

 

[catalyst1]

What exactly happens whe she tries? Does it just do nothing?

 

[TheeOx]

Her main problem is that she cannot open other files in Excel.
Other times she can open multiple files.
When no other files will open, yes it just does nothing.
Whatcha think?