Error code 0141-Hard Drive-No Drive Detected

Hello,

I Have an Inspiron 545, Vista. 2009
It was working perfectly fine, loaded a game then walked off.
When I returned it said
"Boot from CD :
No Boot device avaliable, Press ENTER key to retry
SATA-0: None
SATA-1: Installed
SATA-4: None
SATA-5: None"

When I pressed the power button it switched off immediately.
Switching on again it has the dell loading screen and then repeats the message.
After checking there was nothing extra plugged in, and no discs in the drive... I also checked the wires inside and the connectors and [after a little dusting] everything looks fine.
I then pressed
F12 - Boot Menu - Diagnostic:

Which brought up

"Error Code 0141.
Msg: Error Code 2000-0141
Msg: Hard Drive - No drive detected"
Further scans found nothing else

Has my hard disc just died?
Is there anything at all I can do?
[I didn't want to touch BIOS settings or anything]
I do not have a copy of windows or a backup of any files.
Please help thankyou!