Hi, I have a Lenovo desktop which a little while ago crashed and on boot up I could only get the message "OS not found". I was wondering if anybody has come across this before and if there is a way to re-activate the OS.
Thankyou for taking the time to read this, I look forward to your feedback.
Welcome to the forum. It simply means it's lost the boot sector assuming the disk is ok then download the free ISO from Microsoft boot from it and do a repair
Run Macrium Reflect's Fix Boot Problems utility
DownloadKyhi's rescue iso.
Create a bootable flash drive from it as follows:
1. ------------------------
2. Insert a USB flash drive, 4GB is more than big enough.
3. Open a Administrator Command Prompt. It will say Administrator Command Prompt in the Title bar. Enter the following commands:
4. diskpart
5. list disk
6. select disk # <- replace # with the actual disk number of the USB flash drive
7. clean <- this will erase the disk selected above, make sure you selected the USB flash drive!
7a. If the flash drive shows as GPT then you need to convert it to MBR: convert mbr
8. create part pri
8a. sel part 1
9. format fs=fat32 quick
9a. assign
10. active
11. exit
12. exit - and if the first Command Prompt was not an Administrator Command Prompt, exit that one too.
13. Mount the ISO you downloaded. If you are using Windows 8 or 10, you only have to right click on it and click on Mount. If you are using Windows 7, then you must use a program like WinCDEmu to mount the ISO file:
WinCDEmu - the easiest way to mount an ISO. And more...
14. Copy all the files and folders from the mounted ISO file to the USB flash drive. You can Copy and Paste or Drag and Drop to do this.
Boot the flash drive then start Macrium Reflect from it. Use Macrium's Fix Boot problems utility. I think that will resolve the problem you're having.
Before doing all of that, check the HDD cables. Make sure the power cable is in tight to the back of the drive. Choose a different one to test. Make sure the data cable is in tight to the back of the drive and to the motherboard. Try replacing the cable,. Try a different SATA port on the motherboard.
Run a HDD diagnostic program on the drive, like HD Tune standard Go to the Error Scan tab and do a Full scan, not Quick. This will take time. If any of the blocks come up as Red those are bad sectors. If you are getting several, you will need to replace the HDD.
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