Hello I need help. my computer keeps showing this error msg... Non System disk or disk error replace & strike any key when ready..... I replaced the Hard drive...so I know it is not that. I noticed this happened when i hit restore defaults in my Bios. I have Hp Compaq 6715b. I also noticed it said "media test failure check cables...it says time & date not set....I also changed the cpu battery.. If you mention a hardrive recovery cd...how will this work when the computer wont even boot....including any cd's i put into it...Thanks for your help.