My father and I currently have a stock Dell xps 420
We bought it about 4 years ago and over the past year its has been slowing down a lot. Now it crashes often and is almost unusable. I believe that there are some components in this pc that are still useable and I just want to be able to upgrade so that the speed of this computer improves. We both don't know a lot about PC's and we just want to know some different components we could use the put into the PC.
I would like to be able to game on this computer so I was also wanting to look for a decent graphics card that I would be able to run BF3 on average-high setting that is compatible this PC
Forget upgrading it. 4 years old, I don't even need to know the specs to know its not worth putting any more money into. Thats just the way it is with computers. You can save the hard drive, optical drive, thats about it.
I'd say you could reuse the case, but Dell is famous for proprietary components, the front panel switch button probably would require re-wiring to work as I can almost guarantee you it isn't standardized.
The CPU is going to be an LGA775 Intel Core2 something, that CPU is several generations out of date by now, as is the motherboard. The RAM is DDR2, DDR3 is the current standard, and there is no backward compatibility. You're looking at a complete system build for the best performance for the money.
I would say keep the dvd drive and hard drive, but the hard drive might not even use sata. There is a chance you could use the psu, but unfortunately dell sucks, so that probably won't work.
I can almost guarantee you its a SATA hard drive. But, the other thing about the PSU, thats another proprietary part Dell is famous for. Several years ago, I recall a lot of people even blew up their computers because of it. The PSUs at the time had the standard ATX motherboard main connector, but the wiring pinout was different, so if they installed a standardized ATX power supply in the system, it fried the motherboard/CPU.
Chances are it's a software problem rather than hardware. If you want to check run prime95 and stress test it, than pick up a program to test the HD for errors, actually for that I think windows has a program to do that but fair warning it will take awhile. While your stress testing it monitor the temps, there are programs out there to do that I just use Speccy if I were you, mainly because it has the computer temps but also tell you exactly what the computer parts are so you can tell us.
That should narrow it down to if it is hardware or software for most cases, if it fails prime 95 over 8h it's hardware, if the temps skyrocket and CPU throttle down you need to clean out your case and possibly better cooling (though probably just clean it out if it was fine before).
But more than likely from my experience it's from too many programs autobooting and programs conflicting with each other. So there are a few things I do before giving up hope, easiest way is go download ccleaner and auslogics disk defrag and run ccleaner (after you unselect what you don't want deleted, like browsing history) and than run auslogics disk defrag and "defrag" and use setting to skip fragments larger than 50mb (this program isn't required you can use whatever you like but I like stuff done quickly and normal defrag setting will just defragment fragmented files and not move things to the faster portions of the disk, and things larger than 50mb don't make much difference in speed if any)
Once you do that go into ccleaner under startup and disable programs that are not useful to booting up, such as steam, utorrent, itunes, etc. Drivers and antivirus are things that should be left alone and allowed to boot, if you don't know what it is leave it alone or google it, still don't know what it is don't disable it. Now restart the computer and update the OS and most of your programs. That alone usually speeds up the computers I end up working on.
If your lazy you can go to http://ninite.com/ and have the programs I mention instal on their own after it creates a custom instaler for you. Or if you want you can use your own defrag tool, and go into MSconfig and do what I mentioned with disabling the programs. And use the built in tool to clean up the hard drive of junk files. This is just my personal preference on tools to use, though the overall result should be the same weither you use windows default programs or what I use.
Now for parts you can use I can pretty much guarantee you the HD is usable along if it doesn't have any errors, check for that for win 7 it's called Error Checking and you right click on the C: drive or whatever hard drive you want to check and run it. Though it might have been called something else before like disk check in the past (should be the same thing). If that turns up with no errors you can use it in your new build, you can also use your optical drive (dvd reader/burner) and if you have an multimedia card reader you can reuse that as well most likely. 4 years ago in 2008 everything should have been sata I would imagine that you bought especially for an XPS assuming it still means high end computer for dell.