If you have installed a recent version of Microsoft Office and get a message in Word or Excel that your macros have been disabled, this is why:

A good portion of viruses are written specifically to nestle in Microsoft macros, utilities that can automate some of your work. According to one expert, there are probably 1,300 viruses around whose purpose in life is to invade macros and make you miserable.

Thus, macros are disabled by default to protect you from these viruses. To enable macros, clicking on the Tools menu, then Macros, and then Security.

In the Security section, click on Low.

However, if you do enable macros, be sure that you have an antivirus program running and that you update your definitions at least once a week.