If MSCONFIG closes as well, you may have a known pest/virus.
I am the administrator using Win xP Pro and I have noticed I cannot open Device Manager anymore. I also tried accessing Services in which won't open.I have tried opening these in safe mode with no problem.
In Normal mode I did notice when trying to open Device Manager, the window momentarily pops up and disappears. Any help would be appreciated.
Note: I have also updated Windows to SP2 recenty.