Windows 10 x64 inaccessible boot device, persistant error

ranjan2001

Cyborg Agent
SOLVED
Asus P5B motherboard with updated BIOS is giving me errors since Windows 10 got updated last.
Every time I boot up, 7 out of 10 times I get this error & then I have to wait for it to boot into repair mode from there I choose safe mode then boot then reboot again normally.
I found the part solution here How to Fix INACCESSIBLE BOOT DEVICE Error on Windows - XtremeRain
Once I shut down again & again this is happening so the solution isn't working 100% for me.

To compound the problem 50% of the times my BIOS also gets reset, I changed my CMOS battery assuming its creating problem but even with new battery the BIOS reset is happening & time is forgotten, boot device is set to floppy which is not present hence inaccessible boot device, AHCI gets rest to IDE another reason for inaccessible boot device.

Few of the times I get booting error in BIOS
CMOS Checksum Bad
Overclocking failed! (even though I haven't overclocked my pc)
 
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thetechfreak

Legend Never Ends
You should scan your HDD for bad sectors once. How old is the mobo itself? Might be the case of a failing mobo/RAM.
AHCI gets rest to IDE another reason for inaccessible boot device
Try using a different HDD on your machine and see the failure rate. HDD bad sectors more reboots than you'd think.
 
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ranjan2001

Cyborg Agent
Another reason may be that your mobo is dying,it is very old afterall.
Its 10 years old build so that could be the reason, I never had motherboard died so dont know if this is how it behaves. Any suggestion for what mobo can I replace as rest of all are working fine, infact I upgraded processor & ram just last year.
 

whitestar_999

Super Moderator
Staff member
Only options are used ones in olx or techenclave/erodov forums or zebronics/chinese oems( *www.deltapage.com/content/price.htm ). I would recommend building a new system.
 

patkim

Cyborg Agent
It’s time to simply upgrade… however I just have a few comments/suggestions before you do that.

Did the BIOS reset and Windows 10 Boot problems started together or did the BIOS problem preexist even before?

Whenever you had a successful boot, did you check the HDD for errors and its health? An app like CrystalDiskInfo can help you understand. What were the results?

On Windows 10 do you have any restore points created that you would like to go back to previous state and check?

What is the make and model of your HDD? Most HDD manufacturer have their own tools to check the health of their HDD, may be you can try one of those. E.g. Seagate has SeaTools.

Would you like to install a 30 day trial of Windows 7 just to eliminate Windows 10 OS related issues if any? You may not get Windows 7 now officially from MS unless you have the retail key, however there were mirrors created by some enthusiasts providing the ISOs online also there's a tool by HeiDoc that still can download Windows 7 ISO from hidden MS Links!.

If you think flashing BIOS has created the issue, you may like to downgrade the BIOS to an earlier version (Unless this version is absolutely a must to get your CPU detected, or any such mandatory requirement just in case) BIOS flashing is risky, any issues here and you may brick the board.

Additional checks – Run the system outside of cabinet, Re-seat the CPU. Re-seat the CMOS battery. Measure the CMOS battery voltage using DMM when PC is completely powered off (Mains disconnected) and battery is seated in its socket. If CMOS battery measures 3 V standalone (outside of the socket) but when in the socket it’s less, then may be socket is faulty or contacts adding some unwanted resistance in the circuit.

What if you shut down Windows but leave Mains switch ON keeping the SMPS in standby mode? Does the BIOS still reset after next ‘switch on’ of the PC?
 
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ranjan2001

Cyborg Agent
It’s time to simply upgrade… however I just have a few comments/suggestions before you do that.
I do plan to upgrade this March, however want this PC to work so kids can use this system.
Did the BIOS reset and Windows 10 Boot problems started together or did the BIOS problem preexist even before?
It only started when I upgraded to Windows 10, never had such problem on Win 7

Whenever you had a successful boot, did you check the HDD for errors and its health? An app like CrystalDiskInfo can help you understand. What were the results?
On successful booting the HDD were checked & found no errors, however I disconnected all hdd except the ssd on which win 10 is installed just to check if other disk might be causing any problem, but the problem still remained as it is.

What is the make and model of your HDD? Most HDD manufacturer have their own tools to check the health of their HDD, may be you can try one of those. E.g. Seagate has SeaTools.
SSD is from samsung & samsung software shows no error & shows good health.

Would you like to install a 30 day trial of Windows 7 just to eliminate Windows 10 OS related issues if any? You may not get Windows 7 now officially from MS unless you have the retail key, however there were mirrors created by some enthusiasts providing the ISOs online also there's a tool by HeiDoc that still can download Windows 7 ISO from hidden MS Links!.
I am also thinking to try once installing win 7 & test it with ssd drive & see if the same issue is there or not.

Additional checks – Run the system outside of cabinet, Re-seat the CPU. Re-seat the CMOS battery. Measure the CMOS battery voltage using DMM when PC is completely powered off (Mains disconnected) and battery is seated in its socket. If CMOS battery measures 3 V standalone (outside of the socket) but when in the socket it’s less, then may be socket is faulty or contacts adding some unwanted resistance in the circuit.
I need to check this 3 V standalone however I have changed the cabinet & while doing so the system was test on open bed before putting all in the cabinet.

What if you shut down Windows but leave Mains switch ON keeping the SMPS in standby mode? Does the BIOS still reset after next ‘switch on’ of the PC?
Yes the BIOS still gets reset, specifically the 1st boot device is reset to default "floppy disk" which is not installed hence the boot failure showing INACCESSIBLE BOOT DEVICE Error. I have to manually change my boot settings then when I save & exit, the cmos setting don't get saved & I have to do it 10-15 times to finally get it working. So as of now I am using the computer by not shutting it down at all.

Thanks a lot for taking time out & replying in detail, I really appreciate your efforts to help me in this situation.
 
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ranjan2001

Cyborg Agent
Here you can see none of the HDD is having problem.
 

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ranjan2001

Cyborg Agent
After reading a lot about this problem I have concluded that motherboard bios chip has gone bad & need to be replaced
Bios Chip Asus P5B Deluxe, P5B-E, P5B, P5B-Plus, P5B-V, P5B-E Plus Motherboard | eBay

Or other alternative I am looking at is replacing to G31 motherboard DDR2 ram or G41 motherboard with DDR3 ram, both are based on LGA775 socket.
 
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ranjan2001

Cyborg Agent
Took the motherboard for repair by
Motherboard Engineers : Laptop Repairs | Unique place for all kind of Motherboard, Laptop Repairing | B1/1, Eros Apartment, 56, Nehru Place, New Delhi

They solved the problem by resetting the BIOS chip at hardware level then re flashing it but that didn't solve the problem then they found the problem in the circuit path to bios chip. Repair cost 500/- 1 day I had to leave it with them.
So the problem is solved & it was hardware issue not the software issue.
 

Vyom

The Power of x480
Staff member
Admin
Not to sound pessimistic, but as far as my experience goes, motherboard repair doesn't last long, especially if it's too old. Do keep regular backups of your data, and except for it to fail again. :p
 
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ranjan2001

Cyborg Agent
Not to sound pessimistic, but as far as my experience goes, motherboard repair doesn't last long, especially if it's too old. Do keep regular backups of your data, and except for it to fail again. :p
Makes quite sense, I am giving this PC to kids for watching youtube & internet browsing so my data wont be there on it.
 
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