Sounds like you have a few bugs in your pc that causing all that annoying problems.
Spywares, Adwares, Virus, Malwares, all these can Slow down your pc, Internet connections, downloads, and sometimes will cause your pc to freeze and become unresponsive.
Ok, first if you dont know wat anti-spyware to get, I suggest you get TrendMicro, Kaspersky or Mcaffee. For anti-virus, I suggest you get Kaspersky, a 30 days trial, Avast- free Home Edition, and Mcaffee-Trial. These are the best AV I've known.
If your IE keeps on taking you to Websites you did not intended to go, then its was probably Spyware Addons, or Trojans that keeps on re-routing your IE destination.
I would really suggest you do these things to have your PC free from virus, and spywares, and spy-cookies & tracking cookies.
Note: I would not recommend Norton as an AV.
Good Luck.