Excel 2003
Windows XP Pro SP 2

My Excel 2003 won't allow me to open a spreadsheet and use it.
Here's the scenario:
1) Launch Excel 2003
2) Select spreadsheet to Open via FileOpenbrowse
3) Once the spreadsheet is open the FIRST click for a tab at the bottom or
anyplace into the current spreadsheet locks up Excel. The only way out is to
utilize Task Manager and abnormally end the application. I've logged off and
logged back on and the issue is still there.
Any ideas? I've done an virus scan and I'm seeing nothing. (McAfee online).
TIA