If you use Microsoft Excel (2003) you might have run into a situation where Excel runs extremely slow for no apparent reason. It's happened to me at the office (I help out with tech support) twice now, and the first time it took me way too long to find a sufficient answer through Google. Quick solution: check your printer.

This sounds ridiculous, and I'm sure Microsoft has addressed this problem in later versions of office, but if you found this page, it's probably happening to you. Some of the symptoms or areas in which Excel slows down drastically is simple cell formatting or row / column insertion. Actions that would usually take less than a second take minutes and it becomes really frustrating when you search Google and the answers are all misleading. I've found things ranging from cells apparently empty being laden with data to broken relations. None of this was applicable. It happened even when you opened a new file, and the same files opened on another PC had no problems at all. This is reason enough to assume that the problem was with the computer and not the files.

The culprit is your (default) printer, or in this case, lack thereof. It seems excel is really obsessed with keeping track of your printer, and if it can't find it then you get disastrous performance. Check to see if your default printer is on and connected. If it's a printer connected to a different computer on a network, check if that computer's on and properly sharing the printer. If all else fails, change your default printer to something not dependent on external hardware, like a PDF document maker.

Now try some simple cell formatting or insert a new column. If the problem is fixed, you're welcome. Otherwise, I'm sorry- keep Googling.