So, you cannot log on and you thing that it might be your TCP/IP Protocols.   Perhaps, they are corrupt.  Let's go check them.

1. Go to the desktop.
2. Single Click on "Start" - go to "Settings" - go to "Control Panel".
3. Double click on the "Network Icon" and you should see a screen like the one pictured below.
   
4. Is TCP/IP one of the network components listed in the box at the top as being installed?
5. If not, click on the add button.  You see something much like the image below.
6. Highlight Protocol and click the add button.
   
7. Highlight "Microsoft" in the left window by single clicking once.  On the right side, highlight the TCP/IP.  Click "OK".
8. You should be prompted for your Windows 95 or 98 CD.  This should install the protocols.
9. Restart your computer and try to log on to the internet again.