I have an computer since 2010. In 2015 I added a SDS to the 1Tb hard disc.
Windows 10 Pro, 4Gb memory,intel i3.
Is it worth to buy a new mother board with a i5 , and add some RAM ?

I did some upgrades to my very dated C2Q HP4999T. It got the change to SSD (no HDDs), 8GB RAM, a 1060 TI GPU and it's game capable now.

The 4G is light for today but if you change the motherboard you may lose your Windows license. Can you change the CPU to an i5 and get 8 to 16GB RAM on the board you have?