New Ram and Hard drive installed, random crashes

the video card was added at least a year ago, I have never had a problem with the graphic card.

That points to heating and overheating causes crashes. Intensive gaming is notorious for producing volumes of heat so it sounds as if that's what needs to be addressed. You start with good cleaning and maybe work on airflow as best you can. I also wonder if your RAM has metal heat sinks. If not, that might be something to consider.

that could be what it needs, there is alot of dust inside the computer, i'll be going into town tomorrow and will get some of that compressed air stuff and clean it out. I should point out tho that the 1st time it crashed the computer had just been sitting there idle with no one using it for almost 2 hours.

Also the geek squad tech guy said that to install the ram and 2nd hard drive they had to remove almost everything in the box to install the HD and RAM and then when they were done they put it all back together. maybe the addition of the new equipment reduced the cooling ability of the computer?

Right now its almost noon eastern time and the computer has been on for almost 6 hours and I just got done playing Silent Hunter 5 for almost 3 hours with no problems so I have no idea whats going on lol

Mfg specs indicates minimum Power Supply Requirement: 500 Watt with two 6-pin PCI-E power cables.

Gateway specs indicate your system has a 400W PSU.

My take...you're at or approaching the limits of your PSU's ability to support system reliably.

VAPCMD

If that is the problem how would I fix it? Would I have to buy a new power unit for the computer? Sorry, I'm fairly noobish when it comes to computer tech lol

If this is the problem then I'm going to be upset at best buy for not telling me about this potential problem!

As another update the computer has now been running almost 17 hours and still has not had the symptoms that it showed last night so I don't know if maybe the computer just needed a night to cool down or what!

I would like to thank everyone who has taken time to give me advice, it is greatly appreciated!

Read up about Best Buy's Geek Squad and the myriad of complaints by customers about overcharging and recommending options and services that are designed to inflate your bill. If you live in a town with a Best Buy, you probably have reliable local builders who can do upgrades that you're not comfortable with doing yourself. You do know that your 32 bit XP will probably not be able to use all of the additional RAM that was installed. I also wonder just how the upgrade was done. If you had 2 gbs and they increased it to 4, they either added RAM that might not be of the exact brand and model or they pulled your old RAM and replaced it with matching modules. Do you know exactly how it was done? If they added RAM that wasn't a near perfect match and you already tend to push your system...especially by overclocking...you could have trouble. If they replaced your RAM, guess what could happen with your old modules? They can resell them during bench services. You pay full price + labor and get no credit for what they can reuse. Of course any builder could do the same. What was done to your PC could probably have been done by yourself with a little reading, forum help and basic skills with small hand tools.