It is impossible to provide a concrete suggestion with so little
information.  The slow opening of a file could be due to any and all of
the following as well as many other factors.

    Insufficient RAM to hold the large file leads to numerous
time-consuming saves to virtual memory.

    A virus protection program to blocking the opening of the file until it
has completed a virus threat check on the file.

    Other applications are hogging machine resources. A potential resource
hogging application may be a variation on a computer virus or worm; take
appropriate action.

Most Microsoft Windows operating systems will bring up a list of the
running applications by pressing control+Alt+delete keys simultaneously.

If the problem occurs when opening applications other than Excel, i.e.
if the problem is not specifically associated with using Excel, I
suggest that you seek help from a message board that addresses your
operating system rather than one that is focused on Excel issues.

WindsurferLA