I am very sorry for your frustrations. Windows 2000 is really old. It was released by Microsoft in 1999. Even Windows XP is just two years newer.
Also, there is no ICQ custumer support any more.
You can find an older version on the following links. They are directly from the ICQ servers, so don't worry.
EnglishHebrewGermanIf the language you want isn't among them, just reply.