STK500 windows 10 says driver not digitally signed

Started by josie76, March 16, 2022, 12:59:17 AM

Previous topic - Next topic


Hi, I actually have a few Olimex STK500 programmers and just recently when I tried to use them Windows reverted away from the Olimex driver inf to a standard USB driver. I tried to change it to the olimex provided driver but Windows 10 won't allow a driver that is not digitally signed or has an expired digital signature to work. I tried all of my programmers and all have the same result.
These all worked fine with this same PC and same use of ARVdude just a couple months ago. I also tried redownloading the drivers from the Olimex website but they appear to be the same as Windows gave me the same error, that the driver was not digitally signed.

Can the files on the web site get resigned so they will work again please?


We can't sign the drivers. The good news is that it is still possible to install unsigned drivers. I use Windows 10 and Olimex ISP500 programmers successfully. It is possible to disable the signature enforcement temporarily, install the drivers, and re-enable the enforcement.

The first time installation is a bit tricky but hopefully we can quickly figure it out.

The drivers that we provide are unsigned. Windows 10 has signature driver enforcement enabled by default. To install the drivers, you would need to disable the signature protection temporarily, then install the drivers, then re-enable the signature protection.

1.1. Click the Start button and select Windows Settings (do not confuse it with Start Menu Settings).
1.2. Click Update and Security.
1.3. Click on Recovery.
1.4. Click Restart now under Advanced Startup.
1.5. Click Troubleshoot.
1.6. Click Advanced options.
1.7. Click Startup Settings.
1.8. Click on Restart.
1.9. Once you boot into "Startup Settings" select the number corresponding to "Disable driver signature enforcement"

At this point your computer will restart and you will be able to install non-digitally signed drivers. If you restart your computer again the driver signature enforcement will be re-enabled.

2. After enforcement had been disabled you need to install the drivers (if you restart your computer you need to disable the enforcement again). How to install drivers once the enforcement had been disabled:
2.1. Make sure that you have downloaded and extracted the drivers provided for your exact tool. For example, for AVR-ISP500-ISO, these are available here:
2.2. Connect the ISP500 tool to the personal computer.
2.3. You should now have some COM port in "Windows Device Manager". If you can't identify the entry unplug and re-plug the AVR-ISP500-ISO until you are sure.
2.4. Right-click over the entry for the cable.
2.5. Select "Update Driver Software...".
2.6. Select "Browse my computer for driver software".
2.7. Select the bottom option "Let me pick from a list of drivers on my computer".
2.8. Either click "Have Disk" and point to the place where you extracted the drivers from the archive above OR alternatively pick one of the drivers in the list under "Model", if there are more then one test them all starting each time from step 1.
2.9. Select next, and if a warning pops up select "Install Anyway" and after installation close the window.
2.10. Inspect the new entry in "Windows Device Manager" after the driver installation and ensure that there are no errors or warnings.

Notice that you if you change the USB port used for the ISP500 tool you would need to again disable the driver signature enforcement and install the driver.
Technical support and documentation manager at Olimex