Help! PC not booting up, No OS Files Found - Error 0x490


Don't know if it as coincidence but yesterday I uninstalled McAfee Anti Virus and when I restarted my PC it wouldn't boot up. I was asked to open the start up repair which I did but upon running this is said it couldn't repair it stating -

"No OS Files Found On Disk" with the Error Code 0x490

How can I resolve this without losing all my data, hope someone can help!!

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Reply to: Help! PC not booting up, No OS Files Found - Error 0x490
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Will It Boot Into Safe Mode?

Start the computer and immediately start pressing the F8 key, once per second till a selection screen loads. At the selection screen, use the up/down arrow keys to select Safe Mode, then press the "Enter" key. If it starts in Safe Mode, try using System Restore.. If System Restore doesn't work from Safe Mode, then restart the computer again, using the F8 key at startup and this time, select "Last Known Good Configuration". Press the "Enter" key, then follow the prompts to restart the computer to a time when things were good.

For other options to fix the error you're seeing, see the links below:

Hope this helps.


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Safe Mode not an option


Thanks for your reply. No won't boot in safe mode. When I get to the selection screen neither safe mode or Last Know Config is given as an option.

At the repair console screen I selected command prompt and tried the msconfig instructions in your link but msconfig wasn't recognised as a command

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That's strange

and not good.

Can you confirm that, by pressing F8 you get to a screen that lists all the options available? Similar to the first image in the link below;

It's strange if not, because since you get to the Safe Mode list this shows the hard disk is working and there is something from the OS still available on the disk.

What options can you see in that list?

The problem is, if the system doesn't boot up even into the top option, Safe Mode, then that means your options then become very limited.

How did you get to that Repair Console screen?


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Also try F5. Why?

Just last month it happened. (What?) We encountered a machine that would not respond to the F8 command.

Remembering my MSDN Ninja training I said "try F5". F5 worked and in the screen we then could press F8.

No one knows why this happened but later it was told there was a trojan on the machine.

Remember to try the other methods since with all that malware and badware out there you'll be learning more skills than you ever imagined.

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