Is CIS not yet compatible with Win 8.1? [merged topic]

I tried installing on Win 8.1, and the firewall component says it can’t load.

how can comodo support CIS 8.1 when it hasnt even been released yet? im sure they will once the final build is released.

Usually software developers prep software prior to release. The public beta is released, so I would hope Comodo is working on making sure its software is compatible.

im sure cis will be compatible once 8.1 is released.

Actually you can install CIS on Win 8.1 but you need to change a value under windows registry for the firewall to work.

Run regedit, go to this value
On the right side you will see MaxNumFilters REG_DWORD change it’s value from 1 to 8. Reboot your machine and then install CIS, everything works just fine thereafter.

If you don’t have the above DWORD, you can simple create a new one by right click selecting New \ DWORD name it MaxNumFilters and change it’s value to 8.

Thanks Glavin. That did the trick for me. You are a saviour. My firewall wasn’t working and your fix made it CIS work 100%. I am happy now. :slight_smile:

Wow, that worked. Not sure how you figured that out, but thanks!

Out of sheer curiosity. How did you figure this out?

I tried to install Win 8.1 preview but it stalled and had to roll it back.

Glad it worked for you guys. :slight_smile:

The firewall driver was failing to initialize because the driver wasn’t getting installed under network adapter due to limits imposed by Microsoft on number of network filters that can be installed on windows 8.1. The default value on a every stable Windows OS is 8 but for some odd reason they changed it to 1 maybe because this is a beta version, not sure though.

I just installed Windows 8.1 Pro Preview (x86, clean install), and then CIS from windows store, and i have this error “The network firewall is not functioning properly” that can not be fixed automatically. (then i re-installed the program from web, still same error)

What’s the problem, Doc?

[attachment deleted by admin]

Radut, I merged your topic with an already existing topic. You may find the answer here.

what exactly that reg change does? i think i’ll just wait for a CIS update.

From what I understand this is on Windows end, it sets an unrealistic limit to the number of filters a network adapter can handle, and not on Comodo’s.

Thanks EricJH, i’ll do the change then :slight_smile:

btw, my MaxNumFilters is 2 not 1

Don’t worry the reg trick is safe and its the default setting on windows client and server versions. I’m sure once they release the stable Windows 8.1 version they will rectify this issue. About the value being 2 in your case maybe because I’m using earlier beta version that leaked before the official one which had MaxNumfilters value set to 1. Just set it to 8 and you’re good to go.

[s] I just did the reg change and did not have to reinstall as I just got CIS to fix problem from the red warning and it now says its ok.

That is on 32 bit in VMware player. [/s]

Edit should have looked before posting it still has the red warning.
I just saw the message saying no errors found and posted too soon.
Now to reinstall.


The strange part is that I found this link [ Is MaxNumFilters (max NDIS filters) registry value on Windows 8 removed? ] saying that:

(...) Therefore, we changed the default value of the installed filter limit to unlimited. (When the value doesn't exist in the registry, it is interpreted as "unlimited"). "MaxNumFilters" is still read, and would be enforced if you set its value. In fact, I think this value might be preserved across OS upgrades, so you might find Windows 8 machines "in the wild" with this value still set with a Windows 7 value.

They said it’s now unlimited (no dword set). After installing CIS the first time and finding this thread, I found the value 2 there.

I decided to reinstall Windows, because after uninstalling CIS, the Windows Defender became bogus (it refuse to start after a 60sec timeout).

Now, in a fresh installed Windows 8.1 Pro Preview, I have no dword (didn’t rebooted yet).

I didn’t installed nothing more than: a browser (Chrome), Skype, Splashtop 2 (Streamer and Desktop) and Teamviewer (did only run it once, actually, and not installed).

Any though of which software may have created the DWORD? Or maybe it appear after some reboots?


I found the asnwer myself.

Windows default is unset (unlimited), and after installing CIS, the value is being “increased” to 2.

Now we just need to know if CIS is responsible for increasing this value, or if Windows does this automatically.

If it’s CIS, then CIS is incorrectly assuming that no parameter means 1 and set a parameter as 2. If it’s Windows, then Microsoft was dumb enough to change the default status of of a parameter (8 to not set) and at same time, leaving a “+1” command considering the not set as 1 (while it currently means unlimited in Windows 8.1).

For last, this behaviour has been changed since 8, not only in 8.1. Since CIS currently works fine with Windows 8, then I suspect it performs diferent actions for Windows 7 and Windows 8… Comodo only needs to update the Win 8 trigger to catch 8.1 as well.

I have another problem. An error window after boot.

“NSIS Error” (title)
Error lauching installer (description)

Task manager reveal it’s from Comodo Dragon =(


I launched it manually and it works. Will try another reboot.

Hi friends
I have the last version of CIS but I cannot install it in my windows 8.1 preview version. when the installation progress reaches to 100% an error occurs that says something about fatal error. Is there a way to solve it.

CIS does currently not support Windows 8.1 and issues should be expected when installing it. I do not know if this is related to previous reports about a registry key which needs to be changed, doesn’t sound like it though.