Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Can't install Npcap #1788

BlackXnt opened this issue Oct 17, 2019 · 3 comments


Copy link

@BlackXnt BlackXnt commented Oct 17, 2019

I tried updating my npcap driver by running the newest installer. For some reason the installer fails right on start. I tried manually removing old parts of npcap, such as the service, driver file, dll files but had no success so far. When manually creating the Npcap folder inside ProgramFiles I was able to get the installer log.

Call: 726
Jump: 755
Jump: 758
detailprint: Windows CurrentVersion: 10.0 (Win10)
Call: 62
Call: 1000
IfFileExists: file "C:\WINDOWS\system32\wpcap.dll" does not exist, jumping 194
IfFileExists: file "C:\npcap_install_options.txt" does not exist, jumping 199
Call: 200
Jump: 217
Jump: 234
Call: 238
Jump: 328
Call: 238
Call: 238
Call: 238
Call: 238
Call: 238
Call: 238
Call: 238
Call: 238
Call: 238
Call: 119
Call: 119
Jump: 517
Call: 1338
File: overwriteflag=0, allowskipfilesflag=2, name="C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\modern-header.bmp"
File: wrote 70976 to "C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\modern-header.bmp"
WriteINIStr: wrote [Field 1] State=0 in C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\options.ini
Jump: 533
WriteINIStr: wrote [Field 2] State=0 in C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\options.ini
Jump: 546
WriteINIStr: wrote [Field 3] State=0 in C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\options.ini
Jump: 559
WriteINIStr: wrote [Field 4] State=0 in C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\options.ini
Jump: 576
Call: 1338
File: overwriteflag=1, allowskipfilesflag=2, name="C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\InstallOptions.dll"
File: wrote 14848 to "C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\InstallOptions.dll"
Jump: 594
Jump: 599
Jump: 604
Jump: 610
New install of "Npcap 0.9983" to "C:\Program Files\Npcap"
Section: "WinPcap"
Call: 1079
Jump: 1094
detailprint: Stopping the npcap driver
Call: 1338
File: overwriteflag=1, allowskipfilesflag=0, name="C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\SimpleSC.dll"
File: wrote 62976 to "C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\SimpleSC.dll"
Jump: 1166
settings logging to 0
logging set to 1
Jump: 1327
Aborting: ""
Delete: DeleteFile("C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\final.ini")
Delete: DeleteFile("C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\InstallOptions.dll")
Delete: DeleteFile("C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\modern-header.bmp")
Delete: DeleteFile("C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\nsExec.dll")
Delete: DeleteFile("C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\options.ini")
Delete: DeleteFile("C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\SimpleSC.dll")
Delete: DeleteFile("C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp\System.dll")
RMDir: RemoveDirectory("C:\Users<User>\AppData\Local\Temp\nsv8B3B.tmp")


This comment has been minimized.

Copy link

@dmiller-nmap dmiller-nmap commented Oct 23, 2019

The installer has found the previous installation's Uninstall registry key and is attempting to run the uninstaller. This fails, because you deleted the uninstaller, so the installation aborts. We can add some robustness for this situation, but your solution will have to be to further manually uninstall Npcap by editing the Registry (be careful, you may irreparably damage your system if you make other changes):

  1. Open Registry editor: regedit.msc
  2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\
  3. Delete the NpcapInst Registry key.

At this point, you should be able to run the Npcap installer, which ought to safely overwrite any remaining installation artifacts. I'm not entirely sure this will work for the npcap driver and service, though.

For future reference, when you encounter a problem with the installer, manually removing parts of the install will make it much harder for us to diagnose and help you.


This comment has been minimized.

Copy link

@BlackXnt BlackXnt commented Oct 25, 2019

Deleting the registry key solved my problem, thank you!


This comment has been minimized.

Copy link

@EEaglehouse EEaglehouse commented Oct 25, 2019

Thank you! This has been driving me insane for 3 weeks. Deleting the uninstall registry key solved my problem, too. The npcap service was successfully started after installation.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
None yet
3 participants
You can’t perform that action at this time.