I want to stop MS Word from asking for a virus scan when opening documents. This happens even with documents I have created myself and is really time-consuming. I have read the other posted answers and have set MS Word Macro Security settings to low. I have Norton anti-virus software but cannot locate the menu to disable the scan. Thanks in advance.

From http://support.microsoft.com/kb/329820:

Disable the Turn on scanning for Microsoft Office Documents option. To do this, follow these steps. Warning This workaround may make a computer or a network more vulnerable to attack by malicious users or by malicious software such as viruses. We do not recommend this workaround but are providing this information so that you can implement this workaround at your own discretion. Use this workaround at your own risk.
1.On the taskbar, right-click the Norton icon, and then click Norton Protection Center.
2.Depending on which version of Norton you are using, click Norton Antivirus or Norton Internet Security.
3.Click Settings.
4.Under Additional Options, click Virus and Spyware Protection Options.
5.Click Miscellaneous.
6. Under How to keep Microsoft Office documents protected, click to clear the Turn on scanning for Microsoft Office Documents check box.