Trying To Bypass Windows Log On Screen

While trying to sort out a fairly unimportant problem I have almost wrecked my operating system.

The system:- Windows XP professional with all updates until Friday (now Sunday)
Computer:- Dont know the make, I think it might be Elite with 1.7 dual core processor, 2 Gb ram 300 Gb HD and Nvdia Graphics card, also installed, a TV card, wireles card and A DVD/CD drive.

The problem:- I was trying to bypass the Windows log on screen and sought help in this forum. The advice I was given seemed reasonable so I did it

What happened:- After making the changes the computer booted up properly but when Windows started I got a lot of splash screens and pop-ups as if it were a new installation and to my horror I could not access any of my data.

What I did:- I tried to use system restore but found that all the points I tried could not be restored.I tried shutting down Zonealarm (another post refers to this) which did not help,so I tried to uninstall Zone alarm but could not as apparently a dll has gone missing.So I deleted everything I could find related to Zone alarm and tried system restore again.Disaster.

The log on screen had reappeared and I thought I had solved the problem. Clicked on OK and the screen with only the mouse pointer appeared and stayed there for about 15 minutes, then the desk top picture appeared, nothing else. About 30 minutes later the icons and <Start> appeared. Everything seemed to work and I had found my files again But I am unable to access the Internet or outlook express, the IE diagnostic seems to think it is a question of Firewall. This could be as the Zonealarm Icon is still in the tooltray even though I thought I had deleted the whole of the program.

I would be grateful for help in two areas. First and most important How can I regain access to the net. Second repairing the ridiculously long start up.