My Prolific USB-to-Serial converter has been working well on Windows
XP but refuses to work on Windows 7 64-bit. Windows first complained
that the driver is unsigned:
and after that complained that the driver cannot be installed:
The
root cause is clear - the Prolific USB-to-Serial driver is not
compatible with Windows 7 because it is unsigned. Despite me choosing to
install the driver anyway, Windows still refused to install it. After
half a day trying various suggestions, I finally came up with a solution
1. Go to the registry branch HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Driver Signing\BehaviorOnFailedVerify and set value as DWORD 0. This prevents Windows from rejecting unsigned drivers.
2. Open a command prompt and perform the following commands to enable Windows Test Mode, make use to use "Run as administrator":
4. Reboot your machine and Windows should report that it is running in Test Mode at the bottom right corner:
5. Proceed to install the driver as per normal. Windows should accept the driver and install successfully:
The Prolific USB-to-serial driver can also be downloaded here, in case you're looking for it.
See also:
Using Prolific PL-2303HXA USB to TTL chipset on Windows 8
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1. Go to the registry branch HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Driver Signing\BehaviorOnFailedVerify and set value as DWORD 0. This prevents Windows from rejecting unsigned drivers.
2. Open a command prompt and perform the following commands to enable Windows Test Mode, make use to use "Run as administrator":
- bcdedit.exe -set loadoptions DISABLE_INTEGRITY_CHECKS
- bcdedit.exe -set TESTSIGNING ON
4. Reboot your machine and Windows should report that it is running in Test Mode at the bottom right corner:
5. Proceed to install the driver as per normal. Windows should accept the driver and install successfully:
The Prolific USB-to-serial driver can also be downloaded here, in case you're looking for it.
See also:
Using Prolific PL-2303HXA USB to TTL chipset on Windows 8
