I tried to install com0com - a null modem emulator - on Windows Vista, but failed because Windows Vista doesn't let me install a driver that is not digitally signed.

1. Windows 10 Free Upgrade
2. Windows 10 Problems

I followed these instructions found in the readme file:

Windows 10 Free Upgrade

1. Inactivate UAC
2. Run bcdedit.exe -set TESTSIGNING ON
3. Reboot the computer.

Jul 1, 2011 - The signed 2.2.2.0 com0com drivers can be obtained here. They are compatible with any Windows 10, Windows 8.x, Windows Vista. Attempting to install a signed 64 bit driver on windows 10 preview. When installing the driver from the device manager, the install is successful.

3 Answers

Try running bcdedit.exe -set TESTSIGNING ON in an administrator command prompt (Run as Administrator). Or try: http://www.ngohq.com/home.php?page=dseo instead.

Is 32 or 64 bits Vista? I remember reading in the OSR mailing list that unsigned drivers can not in any way be installed in vista 64 bit.Hope this helps.

For anyone having the driver signing issue on Windows 8, the bcdedit answer above doesn't seem to work because Windows 8 has some sort of new Secure Boot policy that prevents running that command successfully, even as admin (on my machine, at least).

What worked for me was running shutdown /r /o /t 00 as admin, then selecting Troubleshoot, then Advanced options, then Startup Settings. Click the Restart button to restart and enter the Startup Settings menu, then select option #7 (Disable driver signature enforcement). After restarting, Windows should now allow installation of the com0com drivers (though it shows big warning messages that the drivers are untrusted).

(I found the details on getting into the advanced startup settings here.)

Not the answer you're looking for? Browse other questions tagged driversinstallationwindows-vistacode-signingnull-modem or ask your own question.

I tried to install com0com - a null modem emulator - on Windows Vista, but failed because Windows Vista doesn't let me install a driver that is not digitally signed.

I followed these instructions found in the readme file:

1. Inactivate UAC
2. Run bcdedit.exe -set TESTSIGNING ON
3. Reboot the computer.

3 Answers

Try running bcdedit.exe -set TESTSIGNING ON in an administrator command prompt (Run as Administrator). Or try: http://www.ngohq.com/home.php?page=dseo instead.

Is 32 or 64 bits Vista? I remember reading in the OSR mailing list that unsigned drivers can not in any way be installed in vista 64 bit.Hope this helps.

For anyone having the driver signing issue on Windows 8, the bcdedit answer above doesn't seem to work because Windows 8 has some sort of new Secure Boot policy that prevents running that command successfully, even as admin (on my machine, at least).

What worked for me was running shutdown /r /o /t 00 as admin, then selecting Troubleshoot, then Advanced options, then Startup Settings. Click the Restart button to restart and enter the Startup Settings menu, then select option #7 (Disable driver signature enforcement). After restarting, Windows should now allow installation of the com0com drivers (though it shows big warning messages that the drivers are untrusted).

(I found the details on getting into the advanced startup settings here.)

Windows 10 Problems

Not the answer you're looking for? Browse other questions tagged driversinstallationwindows-vistacode-signingnull-modem or ask your own question.