Vista disk

hi all,

i have had a few problems with my laptop and things are kind of sorted out where i can use it again for most things. I still get nervous about it though and thought that if i had an installation disk that i could reinstall it totally if needed be. i thought it would come with one or a recovery disk but it didn't, plus i doubt i could use one with my knowledge anyway. Is there somewhere i could get one from for peace of mind should it conk out on me? it doesn't seem fair to have to buy one just incase as i paid for it when i bought my laptop.
I'm running vista home premium on a hp 6735s laptop.

Thank you

Andy