An issue with your computer is blocking the VAC system.

[Sethioz]

This topic is about the VAC issue that mainly happens in Counter-Strike Global Offensive (CSGO / CS:GO). Exact message is:
"An issue with your computer is blocking the VAC system. You cannot play on secure servers"

I have seen lot of people getting this and there is no known fix or cause. Steam articles are complete bullshit. For me it started about 2 months ago (from this post) when CSGO had an update and haven't gone away.
However I noticed 2 things that help and also what might cause it (in my case at least).

I think Skype or Google Chrome might be the cause, it's very difficult to say, because it doesn't happen instantly, it happens like 10-20 minutes into the game, then it fucks up and throws you out with the message.
I played CSGO for about 2 weeks without error message with only difference is that before playing, i rebooted the PC and did NOT launch skype or google chrome, I didn't get the message. about 30 hours ago, I used skype and chrome, i closed them both and went into CSGO, but got the message. So i think that steam fucks itself up if it's launched after google chrome and/or skype. Once you run steam after chrome or skype, then you're fucked and get the VAC error, reboot PC and don't launch chrome or skype. At least for me it worked for 2 weeks.

However sometimes steam jerks itself up and issue won't go away after reboot, like it happend to me ... once it's there, steam has jerked itself to shit so bad that it won't go away, you have to clean the shit after steam has shitted it all up. fucking pisses me off.

but there's a command to wipe off shit after steam.
exit steam completely > go to start > run > steam://flushconfig > press enter > steam pops up > login > it asks if you want to clean settings > yes > after steam has finished uncrapping, reboot PC.

It means open up run command and type in "steam://flushconfig" and hit enter.
This does not wipe off your games, it just deletes all local settings, such as if you have streaming enabled or not, if you have notifications on/off, steam window size, location ..etc ..etc. It takes 1-3 mins to re-setup these small things, but at least you can play.

I still don't know if google chrome and/or skype has anything to do with this, but that's what worked for me, just don't play CSGO if you have touched google chrome or skype. i got another 7 day ban because of valve is being tardfucked and can't fix their shit, but i'll try again tomorrow in casual to see if this method really works.

FIX:
I just confirmed, I got the issue again, I did close google chrome and skype before playing, but i did launch them within same session and got the issue.
rebooted pc and did not fix. So what fixed it 100%:

1. exit steam and any steam related process
2. run CCleaner with all options on (except wipe free space and no registry clean needed)
3. start > RUN > steam://flushconfig > enter > steam pops up > login and click yes when asked to clean > reboot PC
4. DO NOT start any 3rd party programs, run steam > play CSGO > run any screen recorder if needed.

TeamSpeak and Raptr does not seem to generate this issue as i had both running, played 66mins and no problems, when the issue happens, it happens before 30 min. So i can confirm that these steps work in my case.

So my assumption is that the cause for this, is that idiotic steam manages to conflict it's settings with chrome or skype, once settings are corrupt, then only option is to flush the settings down the toilet. It's stunning that chrome or skype manages to fuck up steam ... seriously steam? go fuck yourselves devs, fix your shit. Now i'm on 4th 7 day ban because of this nutlicker.

UPDATE:
I recently got the error again and noticed that skype has nothing to do with this. In fact, now i'm quite sure that once you get the issue, then something stays in RAM and it can only be fixed by shutting off your PC for long enough so that your RAM will fade.
I had the issue and could not fix ... I rebooted the PC and still was getting the error, then i played some other game for about 1h, then i decided to give it another go, i rebooted the PC again and it worked.
During that time, PC had cleared the shit from RAM and it worked.

So i'm 100% sure that steam / valve is causing that crap. like said, it started around february 2015 and been going on since. It doesn't matter which OS or PC i use, issue always happens. Only way i can play, is if I DO NOT launch CSGO before rebooting entire PC. So i have to reboot before playing CSGO and it's all good ... and i can't touch any other programs, just straight into steam and CSGO. I can use ts, but haven't tried anything else ... I was on 7 day ban AGAIN because of this shitted crap.
it's really getting on my fucking nerves.

VAC just conflicts with something ... but with WHAT?? I got same error on clean win 10 install ....... all i had installed at the time was steam. I specifically tried it when installing win 10. I did clean install and only installed steam and tried playing and got the error (pc had been on for about 30 mins).
so clearly steam / VAC / valve just wanks itself in the RAM and then conflicts with itself and fucks itself up hard and then I suffer from it .... no idea why others don't get this, but it's seriously fucking retarded. I know for a fact that they did something, LIKE I SAID, it all started around feb 2015 after CSGO update, me and my friend got that error at SAME exact moment, we both got kicked with that VAC message. for him .. it never happend again, for me ... it keeps happening all the time.