Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.


Windows 7: Check BIOS ROM for changes/corruption

3 Weeks Ago   #1
derChronostat

Windows 7 Prof. 64bit SP1
 
 
Check BIOS ROM for changes/corruption

Hi,
i hope its ok to post a BIOS-related question. My PC works fine, but out of curiosity I wanted to check my BIOS for changes/corruption via checksum (SHA1).
I got the fresh and identical BIOS version from manufacturer website and checked the hash.
I went to BIOS and saved a backup and checked the hash. Result - hashes are not identical


I checked byte-size of both files - identical
I tried different things (save-changes or not, filenames, several backups within one session, etc) and boiled it down to the situation that apparently every distinct BIOS-session I start, is causing a change to the BIOS ROM. I started several sessions, saved a backup each session and checked the hash. Every single ROM is different, except when I did the backup twice within ONE session.

If every indivdual session yields a different BIOS ROM how can I track BIOS integrity/changes?


Any ideas?


Thanks, Chris


My System SpecsSystem Spec
.
3 Weeks Ago   #2
iko22

Windows 7 x64, Vista x64, 8.1 smartphone
 
 

Hi derChronostat

I am not too sure that both files contain the same information.

The BIOS that you are able to download from the manufacturer's website is the complete Firmware of the motherboard.

However, the file that you are able to save from within BIOS, only contains the custom configuration settings of that BIOS. Therefore, this second file will be different to the first file, so I am not sure as how you got them to be the same size.
My System SpecsSystem Spec
3 Weeks Ago   #3
Paul Black

Win 7 HP SP1 64-bit Vista HB SP2 32-bit Linux Mint 18.3
 
 

Quote   Quote: Originally Posted by iko22 View Post
The BIOS that you are able to download from the manufacturer's website is the complete Firmware of the motherboard.

However, the file that you are able to save from within BIOS, only contains the custom configuration settings of that BIOS. Therefore, this second file will be different to the first file . . .
My System SpecsSystem Spec
.

2 Weeks Ago   #4
derChronostat

Windows 7 Prof. 64bit SP1
 
 

I just used the ASUS EZ Flash 2 Utility within the BIOS to do a backup. That yielded a file with the expected size, identical to the ROM downloadable from the manufacturer website. In the meantime I used UEFITool to compare the content of downloaded and backed up BIOS. The files show obvious differences in the Regions but the BIOS region of both files contain exactly the same Volumes and File-content. I extracted several Volumes and compared the checksums and found that some volumes are identical between the two ROMs and some volumes differ.


I could understand that the EZ Flash Utility is doing some proprietary stuff that results in a slightly different ROM-image than the original but what I do not understand is why it is changing from BIOS-session to BIOS-session.
From my understanding an image of a ROM-chip which is 'read only', hence no custom configuration should be in it.
If there is, I would expect that if I do not change custom config I should at least get identical backups and should be able to compare the backups with each other. Which is not the case



Ok, I was hoping that this would be a relatively straight forward thing but whatever ASUS is doing, it hinders tracking BIOS integrity.
My System SpecsSystem Spec
Reply

 Check BIOS ROM for changes/corruption




Thread Tools




Similar help and support threads
Thread Forum
WU fails due to Store corruption & CSI Manifest Failed Catalog Check
Hello! I've been dealing with this issue for the last 2 weeks and I tried just about everything to no avail. While I was at it, I came across these forums many times and seen members get awesome help so I decide it was time to put my pride aside and ask for help too. I'm attaching the logs as...
Windows Updates & Activation
What to do with unexpected shut down and BIOS corruption
Hi guys, My PC is shutting down unexpectedly. Sometimes do not restart. Last two times tries to start again, but couple of times fails. Starts for a few seconds and stops again. Again and again after show me message that BIOS is corrupted and recovers it. After Windows starts normal. I did...
General Discussion
How do I check for Windows Update file installation corruption?
Hello all, Yesterday, Microsoft sent out a new batch of updates through Windows Update. However, I ran into issues when I tried to manually install the Update to Windows 7 file (KB2868116). Namely, the update seemingly hung on me; I left the update on for 20-30 minutes, but it never progressed...
Windows Updates & Activation
BIOS check - Ethernet adaptor failure
I was trying to install a SSD on a friends laptop and transfer the Windows 7. This laptop had been used for several years but never moved off the desk. I transferred the OS to the SSD, then we turned it around and switched the disks in the bay (HDD out, SSD in). When we restarted the laptop, we...
Hardware & Devices
bsod on wake from sleep + bios corruption
Having searched for weeks on this problem I've registered here after reading your impressive replies to similar problems. The system is a recent build, less than 2 months old, and the problem has occurred from the outset. S3 is enabled in the bios, which is the original Award (F3); rev. F8...
BSOD Help and Support


Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 13:57.
Twitter Facebook