Spyware issue? -- "Explorer.Exe Application Error" -Help!

Hi,

I'm having problems with my Inspiron 6000 and I'm hoping someone can help me.

ISSUE:  When I boot the computer, Windows begins to load and I go to the screen where I can select the user.  I then get an error message "Explorer.exe Application Error.  The application failed to initialize properly (0xc0000005).  Click OK to terminate teh application."  If I click OK, it takes me to my desktop, but there are no icons and no start menu; just the mouse.  Around that time, I also get a McAfee popup that says that a bad file has been found and that I should run a scan.  I'm able to get my Task Manager open and can run McAfee and Adaware that way, but I'm not able to to access icons, the start menu, and can't otherwise use the machine.  Plus, I'm worried that it is now infected and data is being "spied" on.

HISTORY:  Yesterday I was on the internet and after going to a site it looked like there was an attempted download that I rejected.  My personal firewall picked it up.  But then I got a tool bard notice "Your computer is infected with spyware" (little red exclamation).  I ran McAfee and Adaware and found three trojan files dated from 1994.  I deleted and quarantined these, and then shut the computer down.  [Also, when I got the infection, I got a full bluescreen on my desktop with a notice saying that I was infected and a link to an anti-virus software.  I then realized that it was not Blue-Screen-of-Death, but was like a window that I could reduce and close, so I suspected that it was some advertisement]. 

QUESTION:  How can I get Windows to run properly?  Was Explorer.exe corrupted, and how can I fix (via the task manager)?  If I can get things up and running, how do I clean out the problem?  Help!