A new computer could fix your problem, but if you have some sort of infected thumb drive or software or go to a website with issues or internet connection is sketchy then the problems can remain the same with a new computer. If you end up getting a new computer, I'd suggest getting one with Windows 10 as for Windows 7 security support will end in 2019 with extended support in 2020.
https://support.microsoft.com/en-us/help/13853/windows-lifecycle-fact-sheetBefore spending more money though there are a few things to try as listed below. ( Rebuild Clean, Memory Test, and Hard Drive / Solid State Drive Test. )
Curious what has been done so far by throwing money at this to try to fix this. What steps did a repair provider take so far so that we dont suggest the same steps?
Most of the time a complete clean build fixes the issues with the original computer and no hardware has to be replaced. However hardware issues mainly hard drive/solid state drive or RAM can cause problems that carry over into a clean rebuild.
You can check out your hard drive or solid state drive health by downloading and running crystaldiskinfo. If it shows green then all is good. If yellow or red then there is a problem with the drive. If the computer has more than one hard drive there is a tab at the top left to select and test additional drives by drive letter selection.
https://osdn.net/projects/crystaldiskinfo/releases/If the issue is RAM related then creating a bootable USB stick or burning the ISO to a CD or DVD and booting off of that to run MEMTEST86 Version 7.5 Free Edition which can point out memory issues.
https://www.memtest86.com/download.htmLastly if you have a virus that is on a thumb drive, you can reinfect the clean build by attaching that thumb drive to the clean build. So be sure that you are running an up to date antivirus and scan thumb drives and other data that is brought over to the clean build.
In the rare case if none of the above is the cause, then it could be driver related. However given your example of the issues it sounds like hung scripts and processes which driver issues/bugs I have yet to see the cause of.
Last question is are there any other computers that are in your home or office to test with to see if its really just that one computer or all computers experience the same problem which would point the finger to internet connection or network connection issues or perhaps the issue is at the website itself in maintaining a handshake to not corrupt your connection which causes hung scripts etc?
