Try
(It works with Excel 2003 and 2007... should work with 200o too)
Try
Close Excel first and On the Windows Taskbar

1) Start-Run- excel.exe /unregserver -OK.
2) Start-Run- excel.exe /regserver -OK.

See the space between exe and /regserver

You might have to designate a full path to excel.exe (most likely C:\Program
Files\Microsoft Office\Office10)

In that case Start-Run- "C:\Program Files\Microsoft
Office\Office10\excel.exe" /regserver - OK

Note that quotes are required because of spaces in the path

"colin 007" wrote:

OK here is my problem, I have OFFICE 2000 installed on my PC, when i
purchased the PC it also came with Office 2007 trial version. Now i want to
keep the 2007 as it enables me to read 2007 spreadsheets that are sent but
because i have not registered it i am limited in it's use. the big problem is
that even when i have a spreadsheet sent to me produced in 2000 or even 98,
Excel 2007 opens the file rather than 2000, can anyone tell me how i default
this back to Excel 2000?