Yet Another Problem

I am about to throw this thing out the window. Today while working in Quatro, I got an error and lost what I was doing. Now tonight, it had gone to screen saver. When I went to log back on, I could hardly get the logon screen to come up, then it wouldn't let me logon for awhile. Later it did the same thing. And it stops right in the middle of loading things. I ran anti-virus and spyware. I am going to email Dell yet again. They must love me! I did find out where my damaged file is - CWindows/downloaded program files. I see you advised someone else to change from Norton, I think I should probably do the same. Thanks for any suggestions.