Is this an IE7 problem?

I have a Toshiba Satellite laptop that I use at home with a dial up and at work with a T-1 line. I have IE7 and Firefox. Since I downloaded and installed IE7 I have had a problem getting on line. If I try to get online via dial up at home I cannot (I get this page unavailable message), until I do a System Restore, then all is well. Then when I go to the office the same thing happens until I do a System Restore again, then all is well.

I have tried setting the Internet Options to only dial-up and then only not dial up and to no avail. I tried uninstalling IE7 and when I tried to reinstall IE6 I got a message that there was a newer version on the computer so setup would close....and it did.

Anyone have any suggestions or enlightenment?