To get around Windows crashes I store all files I would like to keep safe on a separate drive in my machine. The important bits of that information are added to my Dropbox folder and synced through Mesh to SkyDrive: documents, photos and applications. I keep my music copied over on my parents computers, just-in-case my external storage drive fails that has the more important media backed up and left in the cupboard.
I feel my information is safe; really important stuff is in the cloud, the stuff I can download again(games mostly) is on the D: drive along with media I'm not that bothered about loosing and my C: drive has Windows, apps and games installed that only takes an hour or two to reload.