Battle.net not responding:

• Battle.net is taken down for maintenance from time to time.
• If you receive the error rarely, then chances are Battle.net is either actually down and will be running again shortly, or your connection to the Internet is very poor.
• In either case, give it an hour or so and attempt to re-logon to Battle.net. You should succeed at that point.
• If you get this message every time you try to connect to Battle.net you will want to first try an alternate phone number for your Internet Service Provider (ISP).
• Open the folder where you installed Starcraft and find the file bncache.dat and delete it. Battle.net will re-create this file when needed.
• If that does not help, contact your Internet Service Provider (ISP) to see if there are any problems with their service.