Reinstalling W10 on old Lenovo all in one.

If the pc was mine, I would consider getting an i3 2100 which has 4 threads and a Pass Mark score of 1829 against the 1276 of the Pentium G630 twin core. This is one of the few processors pretty well guaranteed to work in this motherboard. Whether the i3 would run at 3.1Ghz, or stay at the same speed as the G630, 2.7Ghz is anyones guess, as the bios is very limited. Another factor is getting to the socket to change the processor, it looks like a difficult job.
There are no blue USB sockets.

Update, unfortunately, the pc has died. The owner was using it no bother when it went bang, it had lasted about a week, I was unable to get a look at the capacitors in the PSU, so that is the likely source of the failure. I took the hdd out and transfered his data to a USB stick and he decided to replace it with a new one. For his particular use, the cheapest with the suitable screen size will do, he already has 2 spare Office 365 unused with ten months left before he renews. I usually check inside PSU's for impending capacitor problems and stick a label with the date on. The last one I checked the other week is about 18 years old and still looking good.