I can't impress upon you that today's WORMS, virus, trojans, malware, pests, parasites, and other bad software make your choice to not have a full time antivirus very unwise. Some time ago you could practice safe computing and survive, now you can't win.
Please get over this issue since no one can support people in such situation.
You list is very "short" as to the machine. For instance an unused ethernet port can cause such a delay but it's not listed in your list.
Your attempt to run without an Antivirus has cast a long shadow over the integrity of the OS. If I saw such a setup I would:
1. Inventory the machine (RAM, CPU, Power Supply Watts, more.)
2. Use System Restore to when it worked.
3. Have the XP CD handy and run SFC /SCANNOW
4. Run the five tools I noted at http://reviews.cnet.com/5208-6132-0.html?forumID=32&threadID=1313&start=0
5. Enable full time antivirus protection.
Bob
System:
Windows XP Pro SP1 (All updates current)
IE 6.0 (All updates current)
No Anti-Virus application running
No Virus?I checked
All drivers current
No system conflicts
Problem:
Internet Explorer and Windows Explorer delay execution randomly when launched. No abnormal CPU usage during hang?in fact, no CPU usage at all until delay passes. Has no effect on other applications that may be running. Click on shortcut to either application, shortcut remains highlighted after mouse is withdrawn, nothing happens then application launches normally and performs normally. Entirely random.
Any suggestions?
Thanks.
John

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic