.xlsx files "not valid win32 application"

[JACofNoIdeas]

I'm currently running Windows 7 64-bit. I cannot open any .xlsx files. It gives me the warning "...is not a valid win32 application". I'm using Excel 2007.

The default excel save format is .xlsx. Files that are of a different format (like .xls) have this "Compatibility Mode" marking and have some annoying issues.

The only way I can open these .xlsx files is to first open Excel and then go to open and find the file.

When I try to assign the .xlsx format type to Microsoft Excel 2007 in "Control Panel->Default Programs->Set Associations" I click on .xlsx, then go to change program and find microsoft office excel 2007. When I click on that, for some reason instead of the current default changing to Microsoft Office Excel 2007, it changes to 2007 Microsoft Office Component.

 

[office politics]

may have been a known issue since vista sp1?

Vista SP1 - "Not a Valid Win32 Application Error"

 

[JACofNoIdeas]

Logging off and back on or even turning off /restarting the computer doesn't work though ;(.