Laptop Help?

Ok, so long story short my aunt was having troubles with her laptop so thinking it was a virus or something software related I installed a clean version of Windows 7 Ultimate 64 bit (it previously had Windows 7 Home Premium 64 bit). And now it's still having the same problems. Running slow, crashing, blue screen of death, ect... Any ideas of what could be causing these problems? When it comes to computers I can fix anything that's software related. I just have no clue about anything with hardware...

My laptop has this problem, it slows right down, if i plug in my charger it'll sometimes freeze the screen goes black and the speakers just buzz and theres the blue screen of death too. Please tag responses for this id like to fix this.

Has the laptop been taking in for repair lately?
When the did the problem start? What was changed?
What are the computer specs?
Have you ran a diagnostics program to check all the hardware is working correctly?

Upload the dump files from BSODs

C:\Windows\Minidump and C:\Windows\memory.DMP are the typical locations