I deploy a lot of software updates for my work. Firefox and Chrome are usually hand-in-hand with timing of their updates. Most of the time it's one update per month, sometimes they sneak two in per month. When you consider the issues with security exploits/malware attacks, 1-2 a month is not bad.

This statement concerns me. If you are using IE8, try to upgrade to IE11, then something is not right on your system. As Chibi mentioned, a screenshot of the "About" screen displaying your browser's version can help. It will confirm 100% what your browser is (you can also check the file version of iexplore.exe).
If you truly are on IE8 and Microsoft won't let you do an IE11 upgrade because they believe you have IE11, then sounds like your computer needs repaired so you are 100% on IE11.
Let's confirm your browser with that screenshot and get a screenshot of the error you are seeing before going further. It's hard to go to Internet Brands without some basic stuff confirmed first.

How many cars some of us have has nothing to do with us trying to help you. Chibi asked for screenshots early on, you have yet to get us those. The only mention about buying a new computer is if your computer could not run currently supported operating systems and browsers.
Since you are running Win7, Microsoft supports Win7 until the year 2020. The only supported version of Internet Explorer is IE11. If IE is below 11, the first thing is to fix that issue. If it can't upgrade to IE11, then next is to figure out what needs done so it can. So far does not sound like you need a new PC, just might need yours fixed.

BTW - I am still running a desktop I built in 2010/2011 time frame. I built it with XP, then went to Windows 8 and then did the free upgrade to Windows 10. Far from a new computer, but it still runs plenty great for what I do.

 

I have never been able to do screenshots, but here's a copy-and-paste of the error message:

Safari is no longer responding because of a script on the webpage https://montecarloforum.com/forum/. Do you want to stop running the script, or let it continue?

On the laptop, substitute "Firefox" for "Safari."

I don't know how to get to the "About" screen, but I looked at my update history and it turns out I AM running IE 11.

 

If you are running Windows 7, just right click the start menu and type "snipping tool" and you will have the program required to do a screenshot. It's a much easier process than doing print-screen and opening software to paste into.

I can't give IB a ticket, requesting that the scripts get looked into without knowing the exact script that is failing. These websites run a ton of them.

Here are a couple of things to try though:

You can try to disable script error notifications in Internet Explorer
Elsewise, I would recommend running MalwareBytes Anti-Malware, and Spybot Search and Destroy on your machine to make sure you don't have any adware installed.

Finally I would try to update Javascript as well, since most script errors are javascript errors.

 

Yes, I do use Firefox. I still doubt it being an IB issue. Perhaps you need an upgrade install of your OS to repair corruption. You could use an administrative command prompt and type sfc /scannow to check for damaged system files. Check for infections/junkware/adware like Chibi said. Is your Windows 7 fully up to date? Service Pack 1, with all Windows Updates installed? Hardware testing good?

Also, have you tried using Google Chrome?

You could also visit "Internet Options" in the Internet Explorer, go to the "Advanced" tab, and Reset the browser.

Oh, and for the record, I have one car and one truck. Thanks!