Building new gaming computer with components from current computer?

[empspectrum]

Hello, (not sure if this is the write category. Don't really know where to put this)
I made the awful mistake of buying a pre-built PC a while back before I really knew anything about computers, and although I have made some upgrades to it, I can still barely run Skyrim at 1080p on the bare minimum settings, and I have to play other games on low as well, and I frankly am just sick of it and want to start fresh.

But here's the thing, I have 2 hard drives already in this PC now (one with the OS stuff on it, and other with games saved on it) a pretty good PSU (600 watts) and 8 gigs of RAM, so my question is, can I buy a new mobo, CPU (http://www.newegg.com/Product/Product.aspx?Item=N82E16819117372), and a new crazy GPU (something like http://www.newegg.com/Product/Product.aspx?Item=N82E16814125685) and still use all my previously used stuff with no problems? Like will my OS and everything work if I just pop in my already owned hard drives and ram?

I'm sure it's possible, but I just want to make sure from people who know their stuff before I buy several hundreds of dollars worth of stuff and it all not work together properly. Also recommending some GPU's, CPU's, mobo's, and cases would be appreciated

 

[fall0ut3]

First off, if you've bought your PC pre build chances are that your PSU is a complete Chinese firecracker. Second, your OS is titled to your motherboard, so unless you put the old mother board (chances are its old and incompatible) you wont be able to use that OS any longer.
Third, what is your complete specs of the system you have right now, and what is your budget?

 

[X79]

Firstly, how good a PSU is, is not dependant on how much wattage it is noted for.

Check this list for good PSUs

http://www.tomshardware.co.uk/forum/id-2547993/psu-tier-list.html

A good one is vital. Since even if it's 600W, how do you know if that's supplied evenly or not? You don't. Unless you go

for quality items. This gets even more important once you buy new flashy hardware, as the PSU can damage them if it's not a good one.

If you have DDR3 RAM, then yes you can take it from your old computer and use it in the new one. Same for the HDD, if it doesn't use

ancient connectors like IDE. You can download speccy from www.piriform.com if you want to see your specs and show us.

Go for a Z97 motherboard of some sort. Tell us your budget and we'll help you.