Danny Proud

not bad, just wasteful. Not sure what you have, but it sounds as if " Prefer Max Performance" in Nvidea (or whatever it's calling in AMD software) is selected for performance.

run DDU (display driver uninstaller) from Safe Mode and reinstall the latest driver afterwards. 

If you can connect the old drive to your computer, it will be as simple as drag and drop from one drive to the other for the pictures.  Games, you will almost certainly have to reinstall to work correctly.

Don't boot from it, boot from your new drive. Just drag files from one drive to the other.

I'm going to assume it's a SATA drive, and you should be able to connect it.  You should be able to remove it from your old system, take the SATA cable along with it.  Find a free SATA port on your NEW computer motherboard, and then connect the power to the drive.  When booting, you should make sure to boot from the new drive, not the old one you just connected.  If all goes well, you will boot into windows and you should see your old drive showing up as newly detected hardware.  Soon after, you'll be able to access it just like any other drive in your system.

Jayz two cents and others have mentioned something about an OS working from one machine to another but I'm not certain how this works.  Given this info I would know of a way to move everything to the new computer but it would be complicated and cost more money for the software to do it.
 
The easiest thing to do would be what everyone has mentioned, remove the old hdd and plug it in to the new computer then select the new hdd as the boot drive in the uefi and drag and drop.  Programs can't be copied from one machine to another and need fresh installs, however this isn't a huge concern these days with everything being online.  Remember that some internet providers have data caps, mine is 1tb a month so keep that in mind, this is enough data for most use cases.

A 1030 or a 750 would be better, but yeah that should work just fine.

Asus' product page says it all:
The RAM should work, but it will downclock to 1333 MHz instead of running at 1600 MHz.

According to the ASUS website, your MOBO can only support 1333 and 1066 MHz RAM, if you had gotten the R2.0 version you would have been fine.

Likely worth shooting for an i7 of some kind just to get those extra threads if you're going to be using the machine for a while.

You can just put a cheap i5 2400 and you will be golden for a bit at least 
https://www.aliexpress.com/item/Intel-Xeon-E3-1220-3-1GHz-5-GT-s-Quad-Core-CPU-Processor-SR00F-LGA1155/32656897326.html?spm=2114.search0302.3.37.656310d7CEsBWE&ws_ab_test=searchweb0_0,searchweb201602_0_10130_10152_10151_10139_10618_10059_10696_10534_10313_10084_100031_10083_10547_10624_10623_10307_10548_443_10341_10065_10340_10068_10343_10342_10103_10620_10344_10622_10621,searchweb201603_0,ppcSwitch_0&algo_pvid=abec2232-02ec-46eb-9049-c0f4b2cfb361&algo_expid=abec2232-02ec-46eb-9049-c0f4b2cfb361-4

yeah for 50$ it's a pretty good CPU and will hold anything up to a 1060 3gig imo.

Your CPU is terrible, I would highly suggest you save up for an R3 2200G system, which will give you a better CPU with the same GPU performance.

How much watt does your power supply have and also how much ram do you currently have?

PCIE is backwards compatible.
 
What I'm concerned about is your PSU... can you tell me the model?

Has your performence gotten worse or was it always like this?

You're getting low performance because that's a fairly low end card.

Danny -- your system is a bit on the old side, so your not going to get wonderful performance out of that machine running anything except some basic ESPORTS titles.  But as the folks above have said -- basic PC cleaning and maintenance is key to getting what you have working at its peak.  Lets start at the basics.
 
The Windows OS
- Use a program like CCleaner to remove old programs, and anything else you don't need
- Look at reducing any "startup" programs that are likely running in the background eating up memory ( https://kb.iu.edu/d/adlf )
- Only remove programs from startup that you are fully aware of as removal of some driver related programs can reduce your performance
- Increase your PAGE file ( https://goo.gl/gLtEZo )
- Update your motherboard and GPU drivers (as stated above)
- When running games on 4GB of RAM, make sure you close as many open programs as possible before starting -- like Chrome, EDGE, Firefox, etc...
 
The Hardware
- Clean out your PC of any dust or debris that might be hanging around
- A $3 tube of thermal paste -- and about 30 mins to re-apply some to your CPU/Heatsink -- if its not been done since the original paste has been put on the Q8400 it might be time (cannot hurt)
- Here is a LTT video about thermal paste
 
A fresh copy of Windows might not be a bad idea either -- depending on how long your current version has been installed (or what version it is -- W10, W8, W7, W-XP)
 
Best of luck young Padawan.  
 
Newf

What are your temperatures like? Since we're talking 10 year old CPU and 6 year old GPU here, stuff needs to be properly serviced once in a while (cleaning out dust, repaste etc.)

sorry but with specs like these it's normal to get bad performance... try reinstalling drivers just to see if that changes anything but I'm afraid this is as good as you'll get.

Uninstall the drivers with DDU, download the newest ones from Nvidia and install those.