Different Blue Screens:Look Like Blue Screen Appears When To Much Action Is Going On Like Opening Of IE And Outlook

Problem Blue Screen. No new hardware or software installed recently, last Windows vista update was on 01/15. When I start first, PC passes user registration (boots fine) and
does the normal stuff like loading software and starting the wireless internet connection via Netgear, opening some windows/programms I will close. All normal, but than comes a Blue Screen and very fast shut down of system with restart. Hardly can read the message...Look like Blue Screen appears when to much action is going on like opening of IE and Outlook... or open to many windows... or some bad programm/hardware is booting. But when I restart, restart gives a different blue screens and trouble is much earlier or directly after registering to the system.

But all starting or booting turn slower, real slow now. Start in --safe mode with net working-- the PC works, but the PC can't handle heavy workloads, is really slow in action. I cannot open --My pictures-- to see all picture files displyed on screen (2.7 GB) (the process trying to access the files in safe mode is real slow) and when I attempt to transfer the file to a USB stick, the computer is stopping in middle of action (after 50% transfer)..........