I've just registered for the forums in the hope that my recent experience can help others.
I had a problem which appeared suddenly for no apparent reason. My system ran OK but startup was painfully slow, remaining on the XP Welcome screen for several minutes. I searched and found many similar problems but nothing to help resolve it. I installed Bootvis and ran a trace of next boot and driver delays. On the output file I right clicked in the Driver Delay portion and it displayed a useful summary table.
The most glaring thing in this table was that I had many (40+) occurrences of 5 second delays from the WINLOGON.EXE process showing the driver name as fltmgr.sys and aswMon2.SYS. The latter driver is from AVAST antivrus (I was running 5.0.545.)
Well, to cut a long story short (too late, I hear you reply) I removed AVAST, reinstalled the same version and the problem is now solved. I assume my copy had been corrupted but showed no other symptoms.
It took me weeks to find this so in my most altruistic spirit I decided to register and "share." I just hope this helps some other poor soul with their problem.
Regards, Mike.