URGENT! Can't boot computer, "Operation System Not Found" error!?!?

[sunnysky]

My computer had been working perfectly until now. I carried it in my backpack for a little bit, and when I tried turning it on at home, a black screen came up saying "Operation System Not Found." What's wrong??

I hardly know anything about fixing computers. I obviously didn't meddle with the operating system or whatever. I really don't know what's wrong.

I remember you're supposed to press the F2 key. I did, and a screen came up that's titled "Insyde H2O Setup Utility Bios Version R029Q2." I have no idea what that's about so I didn't do anything else.

I'm using a Sony VAIO laptop with Windows Vista.

Please help!

[sunnysky]

I've once taken out my harddrive before to be slaved (and backed up), so I just opened the HD compartment in the back. The drive was loose! It wasn't even connected to the little metal things inside the computer. No wonder why I couldn't boot up my computer. I pushed the drive back into its original position and now everything's working fine. =D

[Computer_Commando]

I was going to suggest the problem was the hard drive.  There should be a retainer of some sort to keep it from coming loose.

[Quantos]

There should be a retainer of some sort to keep it from coming loose.

Or at the least a screw or two.

[Computer_Commando]

Or at the least a screw or two.

I would consider those to be retainers, wouldn't you?  HD compartments usually have a door & a screw to hold it closed.  In this case it's a Sony Vaio, so anything is possible.

[PCGuy]

Computer Commando, your signature is awesome LOL

[Zync]

Before messing around with everything consider when you press F2, does the BIOS register a hard drive?

Also check your boot sequence in the BIOS.  You might have your iPod or USB jump drive or a goofy CD plugged into the computer while trying to reboot and it's trying to boot off of that rather than your HDD.