random BSOD, stop code F4 & 7A, and wont create minidump

Mmm.... seems to be unallocated. Hold on, I'll see if I can get more help.

One more thing before we try partition recovery......test your RAM.

Run a minimum of 8 consecutive passes, preferably overnight, or until errors occur using MemTest86+.

Reference:
RAM - Test with Memtest86+

OK, You will now prepare the AOMEI WinPE on an empty pendrive / CD as you may wish, on a Windows 7 32bit machine.

1. Download and install AOMEI WinPE Builder 1.4. http://www.aomeitech.com/pe-builder.html
Help: AOMEI PE Builder Help

2. Download BOOTICEx86_v1.321.rarhttp://www.freewarefiles.com/downloads_counter.php?programid=95133 and extract it to a folder. The extract will contain the BOOTICEx86.exe file

3. Download testdisk-7.0-WIP.win.zip http://www.cgsecurity.org/wiki/TestDisk_ Extract it to the root of the drive. The drive will have the extracted folder testdisk-7.0-WIP.

Plug in your empty pendrive and run WinPE Builder.

Next > Next


In the add tools screen that appears, expand File and place a tick mark to include Everything - Search engine.
Attachment 346440


Click on Add File to bring the My Tools screen.
Click on Add File in that screen and add BOOTICEx86.exe file. ( the extracted file in No.2 above)
Click on Add Folder and add the folder testdisk-7.0-WIP (the extract at No.3 above)
The screen should show both the added items.
Next

EDIT: Select USB Boot Device > Next > OK ( Missed this step, though it would have been obvious as you proceed. )

The WinPE creation should start. Check that the added items show up in the progress window and allow creation to complete.
Attachment 346444

On completion click on Finish.
Attachment 346445

Note:
If you create the WinPE pendrive on a Windows 64 bit machine it will support both UEFI/GPT boot mode and Legacy BIOS/MBR boot mode.But the tools that you add must be 64bit versions.

If you create the WinPE pendrive on a Windows 32 bit machine, it will not support UEFI/GPT boot, therefore, the bootable Windows PE media that you created only support Legacy BIOS/MBR boot mode.

I have assumed that your Lenovo laptop is Legacy Bios/MBR.

Once you have created the WinPE pen drive, boot your laptop with it. It may take upto 10 minutes for Windows to load before the desktop appears.

Doubleclick on the Windows Disk Management and post the camera snapshot.( The attachment in my post #23 is a camera snapshot. ) If you are unable to take a snapshot, then you have to describe in detail how your HDD looks in it.

EDIT: When you invoke Windows Disk Management, if it asks you to initialise the disk - most probably it will - do not initialise. Just cancel that screen. We will examine the first sector ( The MBR sector) with Bootice and then decide what should be done.)

So get started and further instructions as we proceed.

Thus far, I had created the AOMEI WinPE on three different flash drives without any problem nor would I expect any problem.

Start AOMEI PE Builder after you plug-in your flash drive. (No external HDDs. External HDDs are not supported. And plug out any external HDDs before you run the PE Builder with only a flash drive connected.)

Try a different flash drive.

Also post a screenshot of your Windows Disk Management with the flash drive plugged in for us to examine the issue.

For the time being, you can create an ISO instead of writing it to a CD or flash drive directly and then create a bootable flash drive with Rufus. https://rufus.akeo.ie/ ( I haven't tried it though since I did not face any problem )

I have a busy schedule today - appointment with my designated physician. What else ? :) - and may not respond immediately.