Laptop Acting Up: Playback Device Change When Closing Laptop, Typing Jumps, Dissapearing Files

Hi, I have a Dell M4400 Vista 64bit Ultimate and it started acting up recently


1# I notice that whenever I close my screen, instead of keeping the default playback device as my headset, the sound will return to the internal speakers even if I set the default to the headset.

Any ideas as to what I can do to allow my headset to remain permanently default even after I close the screen?


2# While I type, like I'm typing right now, my typing cursor sometimes jumps somewhere else in the text so that suddenly I'm typing in a different part of the sentence. You might think I'm accidentally touching the touch pad, but I've even covered it up and also this has only occurred starting recently.


3# After I made some changes to stop the extra icons in the bottom right side of the screen and during the same week used a program called "Eraser," which overwrites unused/deleted data on the hard drive for security, many of my programs disappeared or became corrupted. Which of these changes do you think caused these problems and what can I do about it?


I really appreciate it guys, thanks!