Yea, it seems quite a bit slower with any antivirus software installed. I used to use Norton 2003. When ever I disabled it, my boot was very quick. My system would be done with hard drive activity even before USERINIT.EXE was finished and the system was idle.
Now with Avast installed, it seems I'm back to where I was before with Norton. At logon, I'll see one icon appear in the system tray, and lots of hard drive activity, then a few seconds later another appears, etc. Without any antivirus software, my icons will appear about a half a second from each other and the system stops hard drive activity sooner.
My guess is maybe XP is going through its icon cache for the Start menu, although I still see hard drive activity when I actually look at different entries from the Start menu.
Is there a log somewhere, or someway to turn one on, which keeps track of all the files "Last scanned:"?
Would there also be a way to delay the "Scan files on open" until after the system is booted? I understand I wouldn't be protected during this time, but if I'm scanning all file while I'm using the computer, there shouldn't be such a high risk for infection during the boot process.