Routers degrade after each year. Some can go lower but it depends on what your doing with it. Heavy downloading and uploading of extremely large files over the internet, Streaming 1080p an etc. Some of the more expensive routers can handle these demands while others can't too long.
What OS is on the PC?
Is the PC drivers updated?
Is the PC OS Updated with the latest Patches?
Is the Router Firmware Updated?
You can try to do a configuration backup on the Router.
Then do a Factory Reset
Then restore the Configuration from a backup for the Router
If that doesn't work even after a firmware update then replace the router.
Or
You can test your WiFi Network from your PC that is WiFi support.
I use Meraki WiFi Stumbler for many, many years now. It's free.
Don't have to install it, just run it from your Browser, but you need Java Client Installed on that Browser.
Then all you have to do is go to:
http://tools.meraki.com/stumbler#q= (-"
tools.meraki.com/stumbler#q="-) <-example
This gives you a full report by signal strength of all the WAP Wireless Access Points in your area including yours.
80 to 100% is the best
60 to 80% is good
50 to 60 is fair
You would be better off if the signal was 90 to 100%.
If your PC WiFi is acting up you can remove the driver but not delete it. Then reboot the PC so OS can restore the driver settings. Try that first. If that doesn't work then could be the PC WiFi hardware is shot! Those can be replace if you have a MiniPCI or MiniPCI-E WiFi card inside either Desktop or Laptop PC. If not they you need to disable that card in the BIOS and buy a USB WiFi adapter and use that instead to get you back up and running.
