Outlook 07 won't reply or forward

Hello, hope this isn't too much information!

Outlook 2007 will not reply or forward emails, (except one reply I made with a picture attachment). Here's the background:

Windows XP Home, SP2. Recently upgraded from MS Office 2003 to MS Office Home and Student 2007 and Outlook 2007. It worked great. One day later, I went to check emails and Outlook was closed, I had left it running the night before, and there was a "New Hardware Found" wizard window up. I couldn't figure out what it was for so I closed it. Later discovered that no sound is working on the computer, and Outlook will only send new messages, no replies or forwards. Receiving is fine.

Here is the error message:
Task 'Road Runner High Speed Online Account - Sending' reported error (0x800CCC80) : 'None of the authentication methods supported by this client are supported by your server.'

Have since discovered the new hardware wizard is referring to "Multimedia Audio Controller" and/or "PCI Simple Communications Controller." Hence the sound problem.

I spoke with ISP, checked all the settings which are correct, deleted my account twice and re-entered it. Tried to restore to the point after the upgrade and before the strange new hardware wizard. This was listed for that date:
4:58:34 am Installed Windows XP Windows Search 4.0
4:58:07 am Installed Windows XPKB915800-v4.
4:57:18 am Installed Windows XPKB915865

AND . . .the system states that it cannot restore! (I tried at least 3 different restore points.)

Hmmm. Could these two problems be related? Will anyone be able to understand what I've written? :confused