No, I don't have any formulas, macros, or any commands running. I have simple spreadsheets that keep basic lists for myself and my mother-in-law. An example would be my list of audio books and download dates from the Library for the Blind for my MIL or a class list of participants for a recent music workshop that our recorder society held.
My guess would be that despite using Microsoft Office Professional 2002 (a/k/a Office XP) for the last three+ years on this Win 7 Pro x64 computer there might be some incompatibility showing up after one of the Microsoft Update cycles for Windows 7.
As I'm writing this I ran the compatibility troubleshooter and the suggestion was to let Windows 7 run Excel 2002 in windows XP SP2 compatibility mode. Once I OKd that the wizard ran an additional troubleshooting scan and gave me an "issues found: incompatible application Microsoft Excel" message. I then clicked on "explore additional options" but am not going to pursue the suggestions to look online, contact a friend, contact Microsoft Communities, etc. at this time.
Now I have a new problem after running the wizard: When I launch Excel from the Start Menu and not the jump list I get a UAC prompt every time. I say OK and then it opens. I never had that happen before so now the jump list doesn't work and I get a UAC prompt for the Start Menu. I set the compatibility back to XP SP3 and put a check in the box to run the program as an administrator but that still gives me the UAC prompt. I even chose the Restore tab from the properties that offered to set it back to 2010 so I did but I still get the UAC for the Start Menu and still can't use the jump list. Once I click past the UAC and the error message on the jump list I am able to use Excel and open my files. The end result is OK; I just have to jump through more hoops to get it to work.
I don't want to do any more "fixing" that might result in Excel not opening at all. This does not happen to me with the jump lists or Start Menu for Microsoft Word or Access 2002. I had never used PowerPoint on this computer but I just opened it and it was fine.
I guess that Windows 7 is being cranky about the old Excel version so I'll have to live with it for now and consider getting Office 2013 (not 365). Have you used that version yet? I have used Office 2010 at school and I like it so far, not that I've even scratched the surface of all of its features!