First thing to buy for any pc is a reliable backup system and implement it with your system drive being limited to just operating system and installed applications and all other files stored on a separate physical drive or partition. That way your backup images should never be bigger than about 30gb and you can recover from anything from a bad install/malware infection through to a complete system crash in minutes. I've relied on Acronis True Image for years - get a fully working trial copy from here:
Link Removed