Your hardware is sufficient for the job, thus, I'll pursue software.
Run CCleaner, both the Cleaner and Registry portions thereof, and don't fear the computer will not crash and burn. To calm all fears, CCleaner is going to ask you if you want to save a copy of the registry before it "cleans".
Now, to help me get an idea of what all is running, then do following:
LIST OF STARTUP PROGRAMS USING CCLEANER
CCleaner | Tasks icon | Startup tab | click on Save to text file button (bottom right side)
Using the PAPER CLIP icon in the top panel of a Message Reply window, attach the .txt file generated by CCleaner.