Browsers freezing up

I have an old Dell Studio desktop with the Intel Core 2 Quad Q8300 processor. Although it is not supposed to support Windows 10, it appeared to be OK after it was automatically upgraded while I wasn’t paying attention. Seemed to work fine for a few months.
About three weeks ago it started stalling, “not responding”, while using Chrome. Problems got more frequent, until last night I was unable to use online at all. I ran cleaners (CC) and Malware and anti virus, but no help. At first Edge seemed to work OK, but then it had problems too. Update features of programs would also drag on very slowly.
When Chrome would freeze up, it was difficult to close, even with task manager. Task manager would remove the image from the screen, and show the task was ended, but when I checked the details tab of task manager (tm), about five Chrome processes were shown to be still running. I could end task on all but one, every time. It would take five to twenty minutes for it to close on its own. BTW, same think for Edge when it started freezing up on me.
One last clue. I had run DiskMax, which seemed to help the first time I used it. But last night I could not get it to run at all. It gave me an error message saying it could not update, and wanted to know if it could change my proxy settings.
Any help would be appreciated.