Windows Vista Administrator problem?

[Derek]

I am running 32 bit Windows Vista home basic on a Dell Inspiron 530 Desktop computer,

My computer was working just fine yesterday morning, I locked it when I left my house to come back several hours later and try to log on to my account. I saw that my mother had logged on to the guest account so I logged out and tried logging back into my (still running) administrator account and saw that my background picture had changed to a plain blue background so I decided to try to change my it back but it wouldn't work, I could however change the color. Other then that everything still worked fine. So I decided to reboot my computer and log back on to the administrator account the background was back but start menu and nothing on the desktop wouldn't load. So I tried rebooting again and this time everything on the desktop loaded long enough for me to open a program but after a few minutes (about when all startup programs should have just finished loading) everything closed on me. I once again tried rebooting this time opining up task manager at startup but once again everything including tack manager shutdown leaving me to see nothing but my background. So I once again reloaded this time opening the guest account and going through a week back system restore. Once it finished I logged on to the administrator opened Firefox and yet again everything closed. So basically, on startup all presses, including Windows Explorer close, leaving me to nothing but my desktop background and having to manually restart the computer. I'd love a fix for this soon.

Please Help,
Thank you!