I found the following advice yesterday about 2 weeks after I'd given up looking for it:
Q. Lately Word and Excel files (Windows XP+SP2, Office 2000) take 7 or 8 seconds to open. The other day I read that the answer might be to delete the Normal.dot document template file. This I have done and now a blank Excel file opens in a flash! However, Word files whether blank or existing and existing Excel files still take a while and show 'requesting virus scan' in the bottom left screen. I very much doubt that my PC has been infected because I'm careful on the internet and use AVG, Windows Defender, Spybot, Spyware Blaster and Comodo firewall. If you could suggest a course of action to get back to normal rapid opening of Word and Excel files I should be delighted.
Ken Christie, via email
A. The 'Requesting Virus Scan' message can slow things down a bit and it's due to a component in AVG called the Office Plug-in, which scans documents for Macro viruses. These are a genuine threat for those who exchange or handle a lot of MS Office files, but if you feel the risk to your machine is low or negligible then it can be switched off. There easiest way to do that is download the latest version of AVG, run the installation program. When you get to the Add or Remove components stage uncheck 'Plugin for Office' and continue the installation.
Incidentally, the same problem can arise with other antivirus programs and the cause is normally the same. The procedure to switch off or disable the Office Plugin varies, but you will usually find the answer in the program's Help files or on the publisher's support website.
[via The Telegraph]