WinXP Boot Delay

Lately, I've noticed a substantial delay following the black scrolling loader screen and the "Welcome" screen; it's approximately 10-15 seconds. A few weeks ago, I timed the entire boot sequence (post POST) to be 15 seconds...I haven't installed anything new that I recall...any ideas what would be doing this?

EDIT: There is hard disk activity...I also looked through my System Restore points and I haven't installed anything...

The following MSKB articles may be of some help to you...

How to Perform a Clean Boot in Windows XP

How to Perform Clean-Boot Troubleshooting for Windows 2000...this article also applies to XP.

How to Troubleshoot By Using the Msconfig Utility in Windows XP