Windows 7: Operating system not found

My sony vaio is about 2 years old with a Windows 7 64 operating system. I changed the hard drive to a 500GB Toshiba. When I turned the computer back on it said "Operating system not found". I was told to turn off my computer and then restart while pressing F2. The new hard drive showed up on the screen. Then I restarted the computer again while pressing F10 but it says "Operating system not found".

Help please....

It says above, you "changed the hard drive drive". You say nothing about putting the OS on the new hard drive. Did you do that? Or do you mean "you added a second hard drive"?

Yep, I was also astonished. Looks like you haven't reinstalled the OS.

And a few more questions.

Why did you change the hard drive? If there was a problem, what was it?

Did you make the Recovery Disks?

If not, how do you plan to reinstall the OS?

On the chance that you haven't reinstalled the OS to the new HD and need to, either run the Toshiba Recovery disks you made or order from Tech Support, or follow these steps to Clean Reinstall - Factory OEM Windows 7 with everything you need in the blue link.

I would have liked to have heard this story, but I don't think he is coming back.

You need to reply?

First question, do you have the OS installed on your new hard drive?

I do not. I have followed some earlier help and have so far downloaded the installer to a memory stick.........

If the OS is not on your HD, you won't be able to boot. First you need to get Windows 7 burnt on a DVD. Official Windows 7 SP1 ISO from Digital River « My Digital Life Download the ISO file of the appropriate one (Home Premium, Professional or Ultimate) and burn to a DVD. You can then start to install Win 7. Use this tutorial to guide you. Clean Install Windows 7 When you get to the part about "Activate Windows Online", uncheck the box and do not input your Windows Key. Do that later after you are happy with the install. Let us know how things go.

Gregrocker posted a link with all the info you need to install an OS in post # 5.

Personally I would burn your win 7 iso to a DVD.
Set your boot sequence to DVD then hdd in the bios if it isn't already.
Put your newly burnt DVD into the Viao and reboot. It will say press any key to boot from DVD. Then follow the prompts.