quick question

[sunnycalifornia]

I reformatted my laptop about a week and a half ago because it was starting to run really slow. Unfortunately, it is still running very slowly, startup takes a long time (yes, I've done msconfig), shutting down takes forever too, and oftentimes when I start my laptop it will freeze at the wallpaper and when I CTRL+ALT+DELETE to restart it says that explorer.exe is frozen. The only things that I transferred over were all my songs, and my documents and thats it.

The only programs I installed so far are the newest Norton (antivirus + utilities), Windows Defender, Lavasoft Ad-aware. Zonealarm Firewall, itunes, Spybot Search and Destroy, Spyware Doctor, winamp, and Microsoft Office 2007.

Help would be appreciated