7 year old system, repair or replace?

At this point, with multiple parts failing or showing signs of failing, I would begin the process of buying a new machine. I would start with the hard drive, since that is the most important piece, followed by the PSU. You shouldn't have to buy everything at once, but just keep in mind that once you decide to replace the CPU/MB/RAM, you should do so all at once to ensure maximum compatibility. Hope this helps!

According to this:
http://www.tomshardware.com/reviews/cpu-hierarchy,4312.html
your CPU is about two tiers lower than the current offerings from both Intel and AMD. 4GB of ram just won't cut it anymore. I would seriously consider a new build. You can re-use your CPU cooler and case. I would also carry over your HDD and your DVD Burner, but get a new SSD to install the OS to

Good Luck!.

Replacing would be a good choice.

Sell the spare parts to amortize the price of your new PC.

Don't keep your case, just buy something new on the market. These things have changed so much in the last 5 years.

Time to start over.

About the only thing I would keep after seven years would be the heatsink (not the fan) and the case. Unless you wanted to keep it together and use it for something else.

$1000 today will get you a computer that will perform better in every way. Even a lot less actually.

Personally I might fix it up with a new drive and fans and donate to my local re-use place. It is still a great computer for more general use.

If it works and meets your needs I would not replace it, just the noisy fans. The one upgrade that would add the best performance would be adding an SSD as your boot device. Then use the current HDD as a secondary storage devices. It really always boils down to $$$. How much do you want to spend? Another alternative is buy a new MB, Memory, CPU and transfer the other existing parts over.

With the age of the parts, no SSD, and many other figures, I would personally recommend that you replace.In today's industry, $1,000 is a great budget if you are willing to invest that again. If it really does what you need it is your call, but I would recommend an upgrade.

Agreed, I'd buy a new computer instead of repairing failing parts. 7 years is a long time for a PC.

"I want to be able to play titles similar to Civilization VI that are released 5 or more years from now"

That means a whole new PC.

Civ... A man after my own heart.

Time, I think to replace.
I also play a lot of civ 4 and 5.
2.42 also, and am starting on 6.
The key to performance is single thread cpu performance.
A single turn on 5 with many city states can take a very long time.

Today, the best single thread performance will come from a gen 8 K processor.
So far as I can tell, civ 4 and 5 are mostly single threaded.
I5-8350K, I5-8600K, I7-8700K.
They will have 4/6/12 threads respectively.
All will overclock to about 5.0.
If budget is any issue at all, buy a i5-8350K.
You will need a Z370 based motherboard; any will do.
You are likely to need windows 10 for support.
You will need ddr4 ram.
Any speed is ok.

4gb is too small for todays builds. 8gb at least.
If you ever think you might want 16gb, it is best to buy that up front.
Simply adding 8gb is not guaranteed to work.

Your hyper212 is a decent cooler, and I would use it for starters.
But, there are more effective air coolers that will do the job and be quiet about it.
Noctua NH-U14s/ NH-D15s or similar would be upgrades.
Here is the noctua TDP guidelines:
http://noctua.at/en/tdp-guide

A 200mm front intake fan should be providing sufficient intake airflow.
One thing you must do is filter the intake to keep your case clear of dust.
You might want to remove the top 200mm fan.
Too much exhaust capability will tend to draw in unfiltered air from adjacent openings.
All the cooling air that comes in from the front will exit SOMEWHERE, taking heat from your parts with it.

5870 is older and hotter technology.
You could replace it with a slightly stronger GTX1050ti which will be quieter.

If you hope to play on a larger 1440p or 4k monitor, a stronger graphics card will be good.
Your 750w psu can handle any graphics card, even a GTX1080ti.
The older corsair units are not considered great, but so long as it runs, I would not replace it.

Lastly Buy yourself a ssd for windows.

I will never again build without a ssd for the "C" drive. It makes everything you do much quicker.
120gb is minimum, it will hold the os and a handful of games.
But, many things default to the "C" drive.
When a SSD nears full, it will lose performance and endurance.
240gb is the recommended minimum.

If you can go 240gb, or 500gb you may never need a hard drive.

You can defer on the hard drive unless you need to store large files such as video's.
It is easy to add a hard drive later.

Samsung EVO is a good choice for performance and reliability.

I agree with geofelt except for 1 thing. It's a pc, really. You should keep the top 200mm fan and use bios or motherboard software or even something like SpeedFan to regulate fan speeds and keep the top fan a couple hundred rpm slower than the intake 200mm. This'll provide optimized airflow through the case keeping the insides cooler, quieter, yet not create enough draw to overpull the intake fans cfm. This'll allow for what most deem to be a 'positive pressure' setup, minimizing dust collection.

If it's actually dieing, like seeing errors and data corruption etc, then yes, I'd use it sparingly, you'll want to retain as much uncorrupted data as possible.
If it's just getting noisy due to stuff like bad bearings etc then further usage isn't going to do any more damage than is already done until something fails entirely.

Right now, the only important item is the hdd, as that has all your files on it. The rest is headed for the garbage as it's seriously doubtful it can be revamped unless you can pinpoint the exact cause of the issues. The sooner the pc is replaced, the better off you'll be not having to cross your fingers there isn't 's total meltdown of gpu or psu or even cpu etc.