Windows7 64-Bit Memory

I'm fairly pc literate, but I swear when it comes to repairing my own pc I kind of have some difficulties so please bear with me.


I just bought this pc and received it no Wednesday. Since using it, it has crashed 1-2 times every day. The common errors I gets are system_service_exception and pfn_list_corrupt.

From what I gathered it was either my drivers or my memory. So I ran a memory diagnostic test, and it came up with hardware problems both times but when I restarted my pc the first so that it would tell me the errors, my pc crashed immediately with a pfn_list_corrupt error. When I ran it a second time my PC started normally but nothing ever read off to me what the problem was.

I have an HP Pavillion Notebook and am using Windows 7 64-bit with 4 gb of RAM. Any ideas or troubleshooting I can do to better evaluate and fix this problem? I really need this notebook for college soon.


Also my pc is a refurbished pc from compusa



ETA:

My pc crashed again and this time the error was memory_management and the troubleshooting read this:


Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7600.2.0.0.768.3
Locale ID: 1033

Additional information about the problem:
BCCode: 1a
BCP1: 0000000000041790
BCP2: FFFFFA80019D4180
BCP3: 0000000000000201
BCP4: 0000000000000000
OS Version: 6_1_7600
Service Pack: 0_0
Product: 768_1

Files that help describe the problem:
C:\Windows\Minidump\073110-25459-01.dmp
C:\Users\Samanthas\AppData\Local\Temp\WER-48375-0.sysdata.xml