Seeing the “Selected File Is Not a Proper BIOS” message can be pretty confusing, especially when you are trying to update your motherboard BIOS and you are sure that you downloaded a BIOS file from the manufacturer. The good news is that this message usually does not mean your motherboard is damaged.
In most cases, the problem happens because the BIOS file does not match your exact motherboard model, the file is still inside a compressed folder, the BIOS update utility cannot recognize the file format, or the wrong BIOS version was selected. A USB drive with an incompatible file system can also cause trouble.
Before you try anything, it is important to slow down and verify the motherboard model. Installing the wrong BIOS can cause serious startup problems, so BIOS updates should always be handled carefully.
Fix “Selected File Is Not a Proper BIOS”
If you want the quick version, here is what you should do:
- Check your exact motherboard model and hardware revision before downloading a BIOS file.
- Download the correct BIOS version from your motherboard manufacturer’s official support page.
- Extract the downloaded ZIP file and use the actual BIOS file instead of selecting the compressed ZIP archive.
- Format a USB flash drive using FAT32 and copy the required BIOS file to the drive.
- Check whether your motherboard requires a special BIOS filename before using its BIOS update feature.
- Enter the motherboard’s BIOS or UEFI menu and use the correct BIOS update utility.
- If the error continues, verify the BIOS file extension, motherboard compatibility, USB drive, and BIOS version.
The “Selected File Is Not a Proper BIOS” error generally appears when the motherboard’s BIOS update utility examines the selected file and determines that it cannot use it for the current motherboard.
The most common reason is a model mismatch. For example, two motherboards can have very similar names but require completely different BIOS files. A BIOS intended for one model should not be used on another model simply because the names look similar.
Another common issue is selecting the downloaded ZIP file instead of the BIOS file contained inside it. Manufacturers frequently package BIOS updates inside compressed folders that also contain instructions or other files.
The USB drive can also be responsible. Many motherboard BIOS utilities work most reliably with a FAT32-formatted USB drive, particularly when the update is being performed directly from the UEFI environment.
With that in mind, work through the following steps carefully.
Step 1: Confirm Your Exact Motherboard Model
The first thing you should do is confirm exactly which motherboard you have. Do not rely only on a similar-looking model name from memory because manufacturers often release multiple versions of the same motherboard.
If Windows still starts normally, press Windows + R, type msinfo32, and press Enter. Look for BaseBoard Manufacturer and BaseBoard Product. You can also check your motherboard documentation or the model printed directly on the motherboard.
If you are already inside the BIOS, look for the motherboard model on the main BIOS screen.
Once you know the model, compare it character by character with the BIOS download page. Pay attention to terms such as WiFi, MAX, Gaming, Plus, Pro, or a hardware revision number.
For example, go to Start > System Information > BaseBoard Manufacturer > BaseBoard Product and write down the exact information before downloading anything.
Step 2: Download the Correct BIOS File
After confirming the motherboard model, download the BIOS update intended specifically for that model.
Go to your manufacturer’s support page and locate the BIOS or Firmware section. Make sure the page corresponds to the exact motherboard model and revision you identified in Step 1.
Do not choose a BIOS simply because it has a newer version number. Compatibility matters more than having the newest file.
Download the appropriate BIOS package and save it to your computer. If several versions are available, check the manufacturer’s release notes to determine whether a particular version is required for your current BIOS or CPU.
Use the path Manufacturer Support > Motherboard Model > Support > BIOS/UEFI to locate the appropriate download.
Step 3: Extract the BIOS Download
One of the easiest mistakes to make is trying to load the downloaded ZIP file directly into the BIOS utility.
Most BIOS downloads arrive as a compressed ZIP archive. You generally need to extract this archive first.
Right-click the downloaded file in File Explorer and select Extract All. Open the extracted folder and look for the actual BIOS file. Depending on the manufacturer, it could have an extension such as .CAP, .ROM, .BIN, or another manufacturer-specific format.
You may also find a text file containing instructions. Read those instructions because some motherboards have special requirements for preparing the BIOS file.
Use File Explorer > Downloads > Right-click the BIOS ZIP file > Extract All > Open the extracted folder.
Do not rename the file unless the manufacturer’s instructions specifically tell you to do so.
Step 4: Prepare a FAT32 USB Drive
If you are updating through the BIOS interface, prepare a USB flash drive correctly.
Back up anything important from the USB drive first because formatting it will erase its contents. Connect the drive to your PC, open File Explorer, right-click the USB drive, and select Format.
Choose FAT32 as the file system when that option is available. For the simplest BIOS update, keep the USB drive relatively clean and place the required BIOS file in the root directory rather than several folders deep.
You can use the path File Explorer > This PC > Right-click USB Drive > Format > File System > FAT32 > Start.
After formatting, copy only the required BIOS file to the USB drive unless the manufacturer’s instructions say that additional files are necessary.
Step 5: Check Whether the BIOS File Needs Renaming
Some motherboard manufacturers require the BIOS file to have a specific filename before the BIOS update utility can recognize it.
For example, a manufacturer may provide a separate renaming utility or instructions telling you to change the BIOS file’s name. Other systems do not require this at all.
This is important because manually changing the filename when it is not required can create another problem.
Check the manufacturer’s instructions included with the BIOS download. If they say the file must be renamed, follow those instructions exactly.
Use Extracted BIOS Folder > BIOS Instructions > Required BIOS Filename to determine whether renaming is necessary.
If the instructions do not mention renaming, leave the original filename unchanged.
Step 6: Use the Correct BIOS Update Utility
Motherboard manufacturers use different names for their BIOS update utilities. The exact interface depends on your motherboard.
Restart the computer and enter the BIOS or UEFI interface by repeatedly pressing the appropriate key during startup. Common keys include Delete and F2, although the correct key depends on the motherboard.
Once inside, locate the manufacturer’s BIOS update option. It may appear under a menu such as Tools, Advanced, Utilities, or BIOS Update.
Choose the USB drive and select the BIOS file you prepared earlier.
Follow the on-screen instructions carefully. Do not turn off the computer, unplug it, or press the reset button while the BIOS update is running.
Use Restart PC > Press BIOS Key > BIOS/UEFI Menu > BIOS Update Utility > USB Drive > BIOS File.
Step 7: Try Another USB Drive or USB Port
If the BIOS file is definitely correct but you still receive “Selected File Is Not a Proper BIOS,” the USB drive could be causing the problem.
Try another USB flash drive and format it as FAT32. Then copy the correct BIOS file to the new drive.
You can also try a different USB port. If your motherboard has rear USB ports directly connected to the motherboard, those may be worth trying instead of a front-panel USB port.
Use USB Drive > Format > FAT32 > Copy BIOS File > Connect to Rear USB Port > BIOS Update Utility.
Avoid using a USB hub during the BIOS update process.
Step 8: Verify the BIOS Version and Motherboard Revision
Some motherboards have different hardware revisions, and BIOS files can be specific to those revisions.
Look closely at the motherboard itself for a revision number or hardware version. Compare that information with the manufacturer’s support page.
Also check whether your current BIOS version supports the update you are attempting to install. Some manufacturers specify an intermediate BIOS version or special update procedure.
Use BIOS > Main/System Information > Current BIOS Version and compare it with the manufacturer’s compatibility instructions.
If you discover that the downloaded file is for a different revision, stop the update and download the correct package instead.
FAQs
Why does my BIOS say the selected file is not a proper BIOS?
The most common causes are an incorrect BIOS file, motherboard model mismatch, unsupported hardware revision, incorrect file extension, compressed ZIP file, or improperly prepared USB drive.
Can I use any BIOS file from the same motherboard manufacturer?
No. You should use only the BIOS file designed for your exact motherboard model and hardware revision. Similar model names do not guarantee compatibility.
Should I extract the BIOS ZIP file?
Yes. In most cases, the BIOS update utility needs the actual BIOS file rather than the downloaded ZIP archive.
Does the USB drive need to be FAT32?
Many motherboard BIOS update utilities expect or work most reliably with FAT32-formatted USB drives. Check your motherboard’s instructions for the exact requirement.
Should I rename the BIOS file?
Only if the manufacturer’s instructions specifically require it. Some motherboards need a special filename, while others do not.
What happens if I install the wrong BIOS?
Installing an incompatible BIOS can prevent the computer from starting correctly. This is why you should verify the motherboard model and revision before starting the update.
Can I turn off my PC while updating the BIOS?
No. Do not shut down, restart, unplug, or otherwise interrupt the computer during a BIOS update unless the manufacturer’s instructions specifically tell you to do something different.
Final Words
The “Selected File Is Not a Proper BIOS” message is usually related to compatibility or file preparation rather than a permanently damaged motherboard. Start by confirming your exact motherboard model and revision, then download the correct BIOS package and extract it properly.
After that, prepare a FAT32 USB drive, follow the manufacturer’s filename requirements, and use the correct BIOS update utility. If the error remains, try another USB drive and verify that the BIOS version actually applies to your motherboard.
Most importantly, do not guess when selecting a BIOS file.