Is that the only webpage you can't see?
You should never run registry cleaners as you may have done even more damage to your system. Reg cleaners are scams.
The problem is your Web server thinks that the data stream sent by the client (your Web browser) was 'malformed' i.e. did not respect the HTTP protocol completely. So your Web server was unable to understand the request and process it.
It almost always means bad programming of the client system and/or your Web server.
400 errors in the HTTP cycle
Any client (e.g. your Web browser) goes through the following cycle:
Obtain an IP address from the IP name of your site (your site URL without the leading 'http://'). This lookup (conversion of IP name to IP address) is provided by domain name servers (DNSs).
Open an IP socket connection to that IP address.
Write an HTTP data stream through that socket.
Receive an HTTP data stream back from your Web server in response. This data stream contains status codes whose values are determined by the HTTP protocol. Parse this data stream for status codes and other useful information.
This error occurs in the final step above when the client receives an HTTP status code it recognises as '400'.
Resolving 400 errors - general
There is a low-level program bug in the client or the Web server or both. If you do not have access to the source code for these systems, the only thing you can do is refer the problem to technical support people at the companies that developed the systems.
What you can try is to run your web browser (IE7?) without add-ons, this is an option available in Start> Accessories> System Tools> Run IE without Add-Ons. Now try to connect to Google, if it connects it is one of the ADD-Ons that is incorrect, you can try and open IE7, go to tools, then manage add-ons and disable them all, enable one at a time and go to Google, come back out, enable another one until you find the one that is giving the problem. Once you find it either disable it or if it is in the Add & Remove Programs then remove it.
Edited by karbo, 28 January 2009 - 05:52 PM.