An issue with your computer is blocking the VAC system. You cannot play on secure servers.

I'm sorry that I replied so late. yes they may have right to that until I installed the software I had no problem with the steam! however must play at least 10 games to figure out that if more trouble .... but if you are good to connect sure that is the problem !!! I tried to make it work but without reinstalling Killer E2200 Gigabit Ethernet Controller (NDIS 6.30) and still prevails problem!

will keep you update with the information !!!

Thank you !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

You are welcome. By the way, I'm assuming you are playing CS:GO like me, and keep in mind that you dont have to play in matchmaking servers to get VAC errors. You can also play in deathmatch. Deathmatch servers are also VAC secured servers. I've been playing 30-40 matches after uninstalling all iobit softwares from my pc and my VAC error problem seems to be solved completely. If your VAC issue also be solved after uninstalling all iobit softwares and restarting your pc, that means I don't have to uninstall my gigabit etherner controller to be safe. Please play with your ethernet cable instead of WIFI after uninstalling and clearing all iobit folders from your pc and let me know if your problem solved. 

yes that was the problem

thank you for the help ✌️✌️✌️✌️

alienware forum the best

I'm glad I could help you. Happy gaming :)

ERROR COME BACK [8o|]" An issue with your computer is blocking the VAC system. You cannot play on secure servers." 7 days ban !!! REASON ? : YOU FAILED TO RECONECT TO THE LAST MATCH .... ( Removed from my PC : Advanced SystemCare Ultimate 8,Game Booster 3, Bonjour,) 

Did you forget to uninstall Start Menu 8 ?

Yes forget to uninstall Start Menu 8 ...

My bro it's using for playing Asus republic of gamers with the Advanced SystemCare Ultimate 8 ASC Ultimate ( Paid Version )  installed on the PC and working without any problems with the Steam .

It was that I got to write on the forums and I put in fog.........

I noticed that your brother's PC doesn't have Start Menu 8 installed. Thats another strong sign for the cause of conflict. You will be good to go after you get rid of that bad boy. Also, products like iobit system care will mess with your registry which causes high potential of risks on your system. Only benefits of them is psychological and they are just traps for people's wallets. The only thing I have on my PC iobit related is iobit uninstaller. Which is nice and it doesn't conflict with steam. I'll be looking forward to hear from you after you uninstall Start Menu 8 too! If you didn't forget to uninstall it the first time, you wouldnt be coming back here to tell about your 1 week penalty.

This is my brother system configuration :

Processor Information:
Vendor: GenuineIntel
CPU Family: 0x6
CPU Model: 0x3a
CPU Stepping: 0x9
CPU Type: 0x0
Speed: 2395 Mhz
8 logical processors
4 physical processors
HyperThreading: Supported
FCMOV: Supported
SSE2: Supported
SSE3: Supported
SSSE3: Supported
SSE4a: Unsupported
SSE41: Supported
SSE42: Supported

Network Information:
Network Speed:

Operating System Version:
Windows 8.1 (64 bit)
NTFS: Supported
Crypto Provider Codes: Supported 311 0x0 0x0 0x0

Video Card:
Driver: NVIDIA GeForce GTX 660M

DirectX Driver Name: nvd3dum.dll
Driver Version: 9.18.13.4752
DirectX Driver Version: 9.18.13.4752
Driver Date: 5 Feb 2015
OpenGL Version: 4.5
Desktop Color Depth: 32 bits per pixel
Monitor Refresh Rate: 59 Hz
DirectX Card: NVIDIA GeForce GTX 660M
VendorID: 0x10de
DeviceID: 0xfd4
Number of Monitors: 1
Number of Logical Video Cards: 1
No SLI or Crossfire Detected
Primary Display Resolution: 1536 x 864
Desktop Resolution: 1536 x 864
Primary Display Size: 13.54" x 7.64" (15.51" diag)
34.4cm x 19.4cm (39.4cm diag)
Primary Bus: PCI Express 16x
Primary VRAM: 2047 MB
Supported MSAA Modes: 2x 4x 8x

Sound card:
Audio device: Speakers (High Definition Audio

Memory:
RAM: 32721 Mb

Miscellaneous:
UI Language: English
Microphone: Not set
Media Type: DVD
Total Hard Disk Space Available: 365051 Mb
Largest Free Hard Disk Block: 273051 Mb
OS Install Date: Jan 01 1970
Game Controller: None detected

Installed software:
Advanced SystemCare Ultimate 8
Age of Mythology: Extended Edition
Counter-Strike: Global Offensive
Dota 2
ETDWare PS/2-X64 10.5.9.0
Game Booster 3
Google Chrome
Google Update Helper
Heroes & Generals

The steam client working very good with all the programs ......

I know how to differentiate between conflict programs .... working with computers since 2000

I'm sorry for your 1 week penalty but I've already recommended to you to uninstall start menu 8 too. Believe it or not Start Menu 8 is the evil here which is conflicting with Steam.  It doesn't matter if you paid for them or not. If you wanna play on VAC secured servers you need to uninstall ALL IOBIT PRODUCTS from your computer like I said on my first post.

When I uninstalled iobit system care pro (paid version as well) the problem was still there for me. But when I uninstalled Start Menu 8 too, I've been rocking on VAC secured servers without any issues.

First to all i want to thank you for your fast reply. Yes the Start Menu 8 block the Data Execution Prevention (DEP) and the programs working with the Runs as Administrator. 

Hello Degor,

Today played my first commpetitive after 5 weeks :)))
Start Menu 8 (ALL IOBIT PRODUCTS) was the problem

Thank you for your help +++