I am running a 7 year old laptop as my main computer. Works great. I cannot imagine a Windows Vista machine not having the horsepower to access the Internet.

Whether you should access the internet with it or not is another thing entirely. There have been no Vista updates for a very long time. I would be quite concerned about security of the operating system.

If I were wanting to get on the internet with that machine I would run some flavor of Linux on it or I would do a clean install of Windows 10. I don't see any reason why a machine that runs Windows Vista could not run Windows 10. Best of all you can try Windows 10 for free.

My laptop came with Windows 7. I did a dual boot with Windows 10 at some point to see what Windows 10 was like. During that process I discovered that you don't have to activate Windows 10 to get Windows updates. You only have to activate it if you want to be able to do things like personalize the way Windows 10 looks.

I didn't see the need for that stuff so I have never paid to activate it. Still get all of the Windows updates. Have been using Windows 10 exclusively for probably 5 years now.

Doing a clean install of Windows 10 is probably not a walk in the park. You would need to back up all of your spreadsheets and whatever else to some other form of storage. Then you would need to download a Windows 10 ISO and burn it to a DVD or a USB using appropriate software. You can find tutorials on the internet. Then you would have to wipe your hard drive using the Windows 10 installer. Then you would have to install Windows 10 with the Windows 10 installer.

Not a walk in the park if you don't ever do things like that but pretty easy if you have done something like it in the past. If you want to try it I would start with this link:

https://www.microsoft.com/en-us/software-download/windows10