Operating system.
Ubuntu Linux.....google and download, you can burn it to cd or write them and they'll post you one.....FREE you can boot off the disc,or partition your hard-drive and choose linux or windoze on bootup.
regular new versions, each is supported for 18 months ,IIRC.
I've used it for about 4 years- NEVER crashes and pleased to say I don't even know how to work windoze, past 3.11.
Ubuntu, Opera, Firefox, Open Office and millions of "plugins" all free
recognises a printer, camera etc. plays almost any format audio and video and isn't plagued with all the viruses and malware that plague Microshaft machines........I love it.