Solution to the problem that JLINK CDC UART driver cannot be installed normally under win7 system

Describe the problem

Adjust a board today , Need to be in Windows7 Some tools run on the system , There's a new one Windows7 System post installation JLink drive , Failure to install properly occurred JLINK CDC UART Serial driver problem . Access with shift load JLink Component equipment , Able to identify JLINK CDC UART, But there is a yellow exclamation point . use Tera Term The tool can't find this “COM4”. forehead , I have encountered this situation once before , I'm sure I can't get around this time .

Try reinstalling the driver in device manager . The driver is not signed ？？

But this computer has been used before JLink Driven , So there is no problem with the hardware ; This system installation disk has been used on several computers （ It took more or less 10 Years. ）, The previously installed systems have also been successfully installed JLink drive , So there is no problem with the software . Strange ...

Try uninstalling the entire JLink Driver package , Reinstall with the same installation file , The problem remains. .

On the Internet baidu Here is a solution to the problem that the driver cannot verify the signature , Say yes Windows The configuration tool of turns off the function of driver signature .

 One 、 prohibit Win7 Drive forced signature 
     bcdedit.exe -set loadoptions DDISABLE_INTEGRITY_CHECKS
 or    bcdedit /set testsigning on
 Restart the computer 

 Two 、 recovery WIN7 Drive forced signature 
    bcdedit -set loadoptions ENABLE_INTEGRITY_CHECKS
 or   bcdedit /set testsigning off
 Restart the computer 

but , It doesn't work at all .

solve the problem

Later, I copied an old version of the installation package from another computer （JLink_Windows_V644e.exe）, Re install it , Just fine , Work well . Pay special attention here , Before using the old version to install the package , Has recovered Windows 7 Driver signature of the system , So it may have nothing to do with whether the driver signature is turned off .

The cause of the problem may be that my initial installation file was damaged for some reason , As prompted in the previous dialog . Another possible reason is that this version does not properly handle the driver problem （JLink_Windows_V680a.exe）, But I think this possibility is very small , The first possibility is mostly , There is a problem with the storage medium or transmission process in the process of storage .

While trying all kinds of things , I'm still from Segger Download the latest version of JLink software package （JLink_Windows_V694a.exe）...

Just solve the problem .

Reference material

Prohibition and recovery WIN7 Drive forced signature
https://blog.csdn.net/zhangge3663/article/details/100883873