Well, at last I have managed to see WebRep’s tool bar.
The problem was with “WinXP Manager”. I have had to change some settings, related to Network (IE). Toolbars, BHOs, and so on. I had ticked the option to have Internet in Secure Mode (no third parties, or something like that).Then, I have had to untick this option. In BHOs, I could see that WebRep was there, and it said it was well . After changing IE properties and reboot the computer, the Avast WebRep toolbar has appeared. I also allowed Avast program to run within “Allowed programs” in Windows Firewall. Well, the thing is that I have WebRep now in XP.