why is my browser unstable and not responding

Hello, First, the problem could be due to the RAM you have installed. With personal experience with low amounts of ram and High amounts, which can cause file paging, which makes your device extremely slow, and possibly causing instability/crashes. You can check your installed RAM in task manager > performance. If you have a standard amount of ram (16GB+), then try these steps : First, try updating you graphics drivers by pressing Win + X, then device manager, then expand "display adapters', then select your GPU(s) and right click the device and select update driver. After that, select search automatically for drivers. If it is up to date, continue. Next, check windows defender, as that may cause Firefox from being able to write temporary cache files. To check, open windows security, go to Virus & threat protection > Manage settings, and temporarily toggle off "real time protection". if it fixes it, add an exception rule for the Firefox Folder. Next, press Win + R, then while in the dialog, press Shift + enter, then run as admin. after that, paste '''sfc /scannow''' and then wait for the scan to finish, then restart the computer (as another measure for testing) Lastly, if you have finished backing up all your files and passwords, try refreshing Firefox. To do so, go to about:support and select "refresh firefox", and click refresh firefox again to confirm choice.