Arguably, this is off topic. OTOH, any answer may be useful here.

I use Microsoft Office Excel 2003 (11.8342.8341) SP3 on
Windows Vista Business Service Pack 2.

When I open a folder in Explorer,
Organise, Views, Explore, E-mail and Share buttons are provided in a row
near the top of the screen.

When I select a .xls file, the Explore and Share buttons disappear and
Organise, Views, Open, Print and E-mail buttons are provided.

If I select more than 15 .xls files, the Open button disappears.

If I select a mixture of .xls and .xlsx files, the Print button
disappears. (I have the "Microsoft Office Compatibility Pack for Word,
Excel, and PowerPoint File Formats" via <http://www.microsoft.com/downlo
ad/en/details.aspx?id=3. Some correspondents send .xlsx files.)

I infer that registry data controls the presentation of those buttons.

I would value information describing that data.

I would like to increase or remove the Open limit.

At the moment, I want to open 21 files. I can select and open 15 and
then select the rest and open those in the same Excel instance.

This is a longterm niggle for me which has finally irritated me enough
to seek a solution.

Thanks
--
Walter Briscoe