get an external hard drive or if your pc is connect to a network create a shared folder and off load all your files onto your new system. 5 years is almost deadly to the hard drive and fans, but the rest of the components should easily last another 5 years with good maintenance.
I would still get a new PC though I never used a pc past its 6th year, but when you do the hardware to fall apart once one thing breaks down the rest usually breakdown as well, thats why always replace your hard drive every 3 years depending on usuage.
After using macs for over a year I think they just work well. The main problem is finding all the software substitutes for windows(excluding games) and then it works fine. Learning how to get the most out of a Mac might also be a problem after being with Windows for a long while and learning every quirk to it there is
