Windows 7: computer wont boot now

hi guys i have a problem that occured from nowhere , im on my old computer now



i was on my other computer less than 1 hour ago so windows kept lagging and not responding.
done all my cleaners and still the same i done a scan disk check on the next boot up but it never got to that stage it just takes a long time to recodnize the keyboard and mouse then will go to windows is starting...the logo does not appear and thats as far as it will
go. have put the repair disk in its took a long time to recodnise it loaded for a while its still loading now , mite of stopped i aint sure , am able to access the bios

now on bootup it is only detecting the cd rom and mouse and keyboard

went into bios , it isnt showing sata hard disk for a first boot device ,

edit , got into the repair options but the disk did not pick up a window operating system !

Check the hard drive with the manufacturer's diagnostic tools.
Hard Drive Diagnostics Tools and Utilities (Storage) - TACKtech Corp.
HD Diagnostic
Warning: On some motherboard's you will need to set the Sata controller to IDE mode in BIOS for the HD app to work correctly.

ihave hadto adjust for best performance , its almost like i have only 513mb ram installed thats how laggy it is

edit . can i upload some bios information here if so what information should i get . i did leave it on all nite and now it wont boot up again it is looking for the cd rom and hard disk is set to first boot device

i done the seatools disk tests and it failed on the short and the long , bad sectors its saying

3month old computer **** :|

EDIT sent my hard drive back me having to pay postage and package complete joke i would not recomend the site i got it from to anybody not sure if i can mention it so i wont