What can I reuse when building new?

[Divinedoom]

Me and my partner have identical 4,5 year old (bought) computers. On both computers the graphics card needs to be replaced as they are starting to break down slowly (but other then that the computers do still fit our needs). The cases are incredibly small, this already killed the original graphics cards leading us to replace them maybe 2-3 years ago. I might have trouble finding graphic cards that fit, current is gt630 with a height of about 3,5cm and that BARELY fits (like 5mm left between the fan and the floor of the case). This combined with the age of the computers leaves me considdering if we should just bite the bullet and upgrade more then only the graphics card.

Option 1: Search around for something that will fit, change graphics cards and hope we can stick it out for another 1-3 years before getting completely new computers.

Option 2: Get a bigger case, new PSU and new GPU. But reuse everything else: MOBO, CPU, HDD, RAM, optical drive. This should work fine assuming the Motherboard fits the case and i make sure the new PSU and GPU work with the motherboard, right? Would we be able to just boot the pc's with current OS, programs and files still intact? This would leave room to upgrade other things as we want to or need to at a later point.

Option 3: Same as option 2 but also replace the motherboard and CPU (basicly only retain RAM, HDD and optical drive). Looking around some online leaves me to believe this would create problems with the OS (windows 10) since the current machine was store bought complete with the OS. I can't just take our current HDD's and plug them into a basicly almost new computer and expect things to work correctly?

As a sidenote, we are interrested in having 2 monitors per computer. For example playing WoW on the main monitor and browsing/streaming video on the second monitor. What should i think about in terms of parts for this to work smoothly/without lag. More RAM, better CPU etc. compared to a normal 1 monitor settup?

I don't fear the actual process of building new computers aslong as i do propper research beforehand, we can also afford to do so if we deem it the best choice in the long term (both finnancially and performance wise). But knowing what will correctly work together and what not when trying to resuse parts instead of completely building from scratch is quite overwhelming for the likes of me so any help would be greatly appreciated!

[Nellah]

If it's a prebuilt computer, what're the manufacturer and model number of the PC? We can look up the specs and have a look at the case size there.

If there's not a lot of clearance or airflow and/or it's a low profile case, a new case is probably in order. What sort of budget are you looking at? Ideally for something like this you should give us the info requested in the sticky as well, though the description of your choices are fairly thorough.

[Divinedoom]

Current computers:
Packard Bell imedia 6410
CPU: Intel i5-2300 2.80GHz
GPU: gt630 2gb (not the original)
RAM: 8gb
It's not so much the case itself being small (though it is annoying to get in there and switch things out), but the airflow is bad (especially for the GPU). I'm not certain thats what is the issue but it would make sense, i mean 5mm between the fan and case floor can't be optimal. It feels like 4 broken graphic cards in 4,5 year between 2 computers is a lot.

If going for an almost new build it would look something like this:

- Budget: probably around 600-700eur per computer
- Resolution: 1080p main monitor
- Games / Settings Desired: Mainly WoW (ultra shouldnt be a problem there on that budget i think), but would like it to be able to handle other games decently even a few years onwards (though then decent/low settings are acceptable).
- Any other intensive software or special things you do (Frequent video encoding, 3D modeling, etc): Not really. Though as mentioned I would like it have double monitors, not sure if thats more demanding though.
- Country: Sweden
- Parts that can be reused: See first post, somewhat unsure.
- Do you need an OS? See first post, somewhat unsure.
- Do you need peripherals (e.g. monitor, mouse, keyboard, speakers, etc)? No.

[Lathais]

If those were 2500Ks in there, I'd say hang on to them. Since they are not, I would start from scratch.

Also, I am not sure on W10, since they are treating it differently I think. You may be able to move it over with a simple phone call to re-activate and maybe not. I know you could with previous versions of Windows, even on OEM versions despite what people say. Just not sure about W10 yet since I have not even heard of anyone needing to move it to a new machine yet.

[Divinedoom]

I have pretty much decided to atleast go for new towers.

Though now i have to decide if i go for a new tower and PSU (choosing parts that i know will last for future builds), get a decent GPU and then call it a day. The advantages there are it will be much cheaper in the short term (as mentioned the computers are still sufficient for our needs if they wern't having issues). Also preferably would not have to deal with getting a new OS, reinstalling all programs etc.
This would leave room to upgrade the rest at a later date when we feel it isn't sufficient anymore, and it should save money in the long run aslong as the parts i order now can be reused when doing the later upgrading.

The alternative is to basicly build entirely new computers. I could probably reuse the RAM and optical drive. Could reuse the HDD if i can somehow get the OS off of there asuming the current OS won't work. Advantage is that we get much better machines now, could for example include an SSD for the new OS and a few main programs. Disadvantage is that it will cost a lot more and be a lot more work.