I have a HP G60-235DX and i'm i the middle of a start up repair but it was givinig a startup...

I have a HP G60-235DX laptop and sometimes it loads asking for a bootable disk. Now my ?? is after it goes threw the

proceedure loading the boot disk and loads the files, Why does it ask me for a media file and where do i get it..My computer

normaly good but for some reason it's can't seem to find the HARD DISK, is there anything i can do to fix that..so its 2 qustion i see,

What and where do i get a Media CD ? and

what can i do to fix the finding the HARD drive

Issue.

I bought it window Vista but i upgraded it to Win7
 then the problem started like a month after that..

Thanks smokinnnnnnn