Computer Acting Up!!!!!

I'm running Windows Me and have recently experienced some 1st time problems:
1. Occassionally I'll double click on a program (ie WordPerfect) and it will open multiple times. This hasn't happened lately.
2. While on the internet, the computer momentarily freezes. I just now experience a brief freeze while writing the previous sentence. I've deleted the temporary internet files and it still happens
3. While operating the system, it will get the "trembles" and shut itself down on its own. This hasn't happened lately.
4. While shutting down, my internet dial-up starts.
Am I in for a complete crash??? Any help will be appreciated.