Annoying excel

Currently using the old windows vista. Had massive problems with my excel 2007. Apparently it keeps stop responding as soon as I open an excel file. Besides, after I've done my work and saved it, and once I clicked the 'close' button, it stopped responding too. Wtf.

The following is the error details I extracted out:

Problem signature:
Problem Event Name: APPCRASH
Application Name: EXCEL.EXE
Application Version: 12.0.6535.5002
Application Timestamp: 4bd2a7f1
Fault Module Name: OLEAUT32.dll
Fault Module Version: 6.0.6002.18005
Fault Module Timestamp: 49e037da
Exception Code: c0000005
Exception Offset: 000046b0
OS Version: 6.0.6002.
Locale ID: 1028

Additional information about the problem:
LCID: 1033
Brand: Office12Crash
skulcid: 1033

Update: I've sent an email to Dell asking what is exactly happening and here's what they replied to me:

Thank you for your reply.

The reported issue happen too long ago and it is not advisable to perform system restore in this case.

I would suggest to backup all data and reinstall the Windows, due to the registry is currupted and cause error when launching the MS Excel and Word.

So I guess the only thing I can do now is to reformat my pc? What a brilliant suggestion.