[brendanprich]

hello!! I would seriously appreciate anyones very detailed and specific information/instructions on how to resolve this problem. I am fairly familiar with computers, but by no means would I consider myself an expert. So, if you can help with my problem , please be very specific with step by step instructions (detailed) on what I should do. Thank you.
Ok. My system is an HP running a Pentium Dual core 2.5 ghz, with 3 gigs DDR2, and NVidia Geforce 210 512mb video, with 500 Gb Hd.
I upgraded from Vista in November, to 7 home premium with no problems at all. over the course of the past 4 months since I installed Wdws7, I have been testing out different anit-virus software programs(utilizing companies free month demos) to find my favorite option. Anyway I recently used AVG, and when the trial was about to expire, I uninstall ed and then installed windows defender. well as soon as I uninstalled AVG the next time I rebooted I had issues with startup. basically windows had to search and repair to be able to load the OS. Well this happened 3 times and everytime the windows 7 OS would eventually load and say the problem was fixed. well on around the 4th shut down and restart day, it finally would not load at all. SO eventually I had to re-install windows 7 , on a my Hd after setting up a new partition. anyway that worked great for about a week, but now everytime I come back to my pc after being away for multiple hours, it has completely shutdown, and when I go to re-start it gives me blue screen and says memory dump, and then makes me choose how to run startup. here is the problem signature: 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: e4
BCP1: 0000000000000001
BCP2: FFFFFA8004076600
BCP3: 0000000000000000
BCP4: 0000000000000000
OS Version: 6_1_7600
Service Pack: 0_0
Product: 768_1
Please help!!!! and tell me step by step what to do!!