We would need to know what MBoard it is to check on what's doable...
You might be able to upgrade to a Quadcore like a Core 2 Quad, but it all comes down to what motherboard you have and what it supports as patio stated. Your CPU is a socket 775 as the Pentium E5300. I have two of the 2.7Ghz E5400 systems and I havent tried them with 10, but they show that they are on the weak side of processing power with Windows 7 and video games I have played on them.
You might be able to upgrade to a Core 2 Quad such as this one linked for around $80, but it all comes down to what motherboard you have. By the way the Core 2 Quad is an old CPU, but it was top of the line way back in 2009.
http://www.ebay.com/itm/Intel-Core-2-Quad-Q9650-3-00GHz-12M-1333FSB-Socket-775-SLB8W-CPU-Processor-/221861107674?hash=item33a7f3d7da:g:OOoAAOSwI-BWJGxAYou might also need to upgrade the CPU heatsink was well to keep this CPU cool running. The E5300 is a much cooler running CPU than the Core 2 Quad.
It also might make more sense to buy a new computer which will give you Windows 10 with a warranty, probably a larger hard drive, as well as more RAM. So it depends on what you have for budget to work with and what games you want to play etc?
