J-Walk & Associates, Inc.

Excel And AV Software

I got an email last week from Joel Klein, a rather frustrated Excel user. He was having some annoying performance problems with Excel. At first he blamed Vista:

There is very little information out there (that I can find) that discusses the operating system environment in which Excel is run. For example:

• In Windows XP, if you select a large (200,000 cell) range and either Delete or Clear All, Excel responds quickly and fluidly.
• In Windows Vista, if you try this, Excel hangs.
• If you do the same thing using VBA commands, XP is again very fast, but with Vista there is a noticeable pause (less than a second).

This is on multiple Vista-based machines with all of the Aero nonsense turned off, 8 GB RAM and a sturdy graphics card.

I've never noticed a problem like that. Thinking that it might be something unique to his file, I asked Joel to send me a copy. I couldn't reproduce his problems (using Vista and Excel 2007). All of those actions occurred instantly on my system.

Then, on a hunch, I mentioned that he should try disabling his anti-virus software. He wrote back:

Fascinating. First, I disabled McAfee. No change at all. So then I was playing around with a few other things, all to no avail, and then I figured I'd just uninstall it altogether. Problem solved.

I still think it is an interesting resource allocation problem for discussion among people who know more than me. Virus protection software scans files. The total CPU burden seemed low (based on the Task Manager).

It is not sucking up a lot of RAM (why would it?). So what has virus protection software got to do with the data in a spreadsheet? Especially if it's totally (allegedly) disabled? And why would it be different between deleting worksheets versus large single-sheet ranges? Is there a way to split the difference -- to have some virus protection but not hobble a key application? Finally, I had the same virus protection on my XP and it never did this!

I've never used anti-virus software, so I have no answers. Joel and I would both be interested to hear about the anti-virus software experiences of others.