Dell Latitude D630: problems turning on, shutting down, logging off and installing updates

I just bought a reconditioned Latitude D630 with Windows 7 and have just a few programs installed: Office 2013, Skydrive, Adobe Acrobat Reader, Flash (which I uninstalled), Skydrive, and McAfee for security.

When I start up the laptop, sometimes the Welcome screeen (after I type in my pasword) just sits there forever, and I have to turn off the laptop with the on/off switch.  Similarly, when I log off or shut down, the "Logging Off" screen sits there forever, and the "Shutting Down" screen just sits there forever.  The laptop also won't process Windows updates; when shutting it down, the "Installing Update 1 of 9" or the like screen just sits there forever.  (I also tried downloading updates while I was using the laptop, but a radio box stating "Installing Update 2 of 9" appeared and sat there forever.)

I can manually turn off the computer and restart it in safe mode, and I've hit the Microsoft button and R and then typed in MSCONFIG, and I've gotten the laptop to start fine by starting up only basic programs, but then Internet Explorer won't work.

I'd really appreciate any help/advice, as I just bought this and am very frustrated. 

Thanks.