Randomly "minuses"? Minimize? (shrink to the taskbar?) Sorry not familiar with the term. But if it is minimizing seemingly randomly, it sounds like spyware/malware or even a virus to me. Most likely spyware though, trying to open/access something through IE or explorer. Have you been using anti-spyware on your system at all? Anti-virus too for that matter? I know it's simple and most people do, but then again not everyone does.