I just setup a new Dell computer running Windows 7 64-bit copied over the data using Microsoft's Easy Transfer then installed Microsoft Office 2007. However, now when opening an existing Excel 2007 spreadsheet, Excel appears to hang for over a minute before any changes can be made.

Are there specific settings that need to be mande to ensure that Excel 2007 will respond normally? Word and Outlook both appear to be working fine and responding well.

One note, I did find that one of the two spreadsheets affected was being saved in the Excel 97-2003 format and I updated, thinking that it could have been the problem. However, both continue to be problematic. For reference, one of the spreadsheets just has data (no formulas, etc) and the other has a number of formulas, primarily =SUM.

Any help would be appreciated.

Is this happening only with existing files? Any problems when you create a new file? Network drives involved at any point here?

Network drives are not involved. This is happening to existing files and we have not tried creating new files yet.

Check what add-ins are loaded. I've had issues with addins after installing Excel 2007.
I can't remember if it was solved when I re-saved them as 2007 add-ins or not.

Okay, no clean install of Excel, there is nothing special about this spreadsheet and a new spreadsheet with <10 formulas (very simple =sum) is giving the same problem. Thanks for your input.

Does it have any hyperlinks? Especially ones that aren't valid? If you save an empty workbook and they try to open it, do you get the same delay?

I haven't tried a blank workbook yet. I'll try that and let you know.