Hi Mark,
The WEEKNUM function requires the Analysis Toolpak add-in to be loaded.
Choose Tools/Add-ins from the Excel menu and put a check mark beside the
entry called Analysis Toolpak (not Analysis Toolpak - VBA). If you don't see
this entry you'll need to install it using your original installation disks.

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Rob Bovey, MCSE, MCSD, Excel MVP
Application Professionals
http://www.appspro.com/
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> My spreadsheet that was used on Windows 95 sucessfully
> has a problem in Windows XP Professional with the WEEKNUM
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>
> Mark Maiden
Mark Maiden - 21 Jul 2003 20:44 GMT
Dear Rob
Yeh! That did the job. Now I can enter Week Numbers again
[I added Analysis Toolpak]
Many thanks
Mark
>-----Original Message-----
>Hi Mark,
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>
>.