ME to XP Pro Upgrade Glitches

Greetings;

I recently upgraded a ME workstation to XP Pro. It went pretty smooth, although I think there is a problem with IE that causes problems with other applications. Things that don’t work: Windows Update gives a blank page and says done; NSW antivirus options page the links don’t work. MS MSGR says “Web Error” when I try to sign on. Quickbooks Pro 2002 hangs the “Company Navigator” page on startup, Office Update gets to 50% of the scan then quits. I’m not a super-expert but I see acommon thread of IE in all these problems. Thanks in advance for your help!