You can make a boot device for free, and put it on a flash drive so you can reuse it or put an updated operating system on it in the future, Then keep it around for just these emergencies.
If you have a laptop that's middle-aged, like 10 years, you could have problems finding an up to date, safe operating system to reload on it. What I do is erase the original OS and put a beginner's distribution of Linux on them. You can try a couple and see which you like. Best to start with ZorinOS, Linux Mint, Pop!_OS, or Ubuntu. All are free to download.
There's an easy way to make a bootable drive. Find a working computer attached to the internet, download and install the Ventoy program onto your flash drive. Then you can download one or more operating system ISOs from the distro's websites. Most other ISO installing software has to add extras that enable you to boot from it, but Ventoy does it for you.
When you boot from the flash drive (you may have to hit the function key that lets you do this, like F12 or F2, or escape or something, whatever appears on your screen), Ventoy gives you a menu of ISOs on your flash drive that you can boot. Try one, and if it works you'll have a fully functional OS with the stock apps it comes with, and you can use that to get back to work, but you won't be able to save anything. Nothing will be installed. This is a good time to explore your hard drive, see if it's OK, and backup anything on it to another drive.
When you've backed up and see that your HDD is OK, you can install the OS onto the HDD and you're back in business. Ventoy also works with Windows ISOs (I haven't tried). But after trying Linux for a while you won't want to go back to an obsolete, bloaty OS like Windows 7.
I'm writing this on my 10 year old Chromebook running Linux Mint.