first thing I'd try on your  computer would be to run msconfig.

Without knowing which operating system you have I hesitate to elaborate.  Basically though you run msconfig.exe, click on the startup tab and remove the checkmark from every box.

Reboot and it should stop all the programs you have running at startup from starting.  They'll still be there if you need them.  If you find you needed something to start at startup just run msconfig.exe again and put a check back in the box for that program.