Found a very old pc. Looking to "modernise" It

Hello everyone. Yesterday I found this old piece of tech lying all dusty and I was curious how far I could push it. It has a MSI g41tm-p31, 4gb of DDR2, intel pentium e5700. I read in the manual online it has a pcie gen 1 so it can only go up to 250mb/s. Keep in mind this isn't a serious build but rather a fun project. Thank you