The .exe extension on a filename indicates an executable file. Executable files may, in some cases, harm your computer. Therefore, please read below to decide for yourself whether the acs.exe on your computer is a Trojan that you should remove, or whether it is a file belonging to the Windows operating system or to a trusted application.
The process known as Agnitum Outpost Service or Atheros Configuration Service or ACU Configuration Service or D-Link Configuration Service or 802.11 WLAN Configuration Service or Ekahau Configuration Service or Belkin Wireless Utility or Agnitum Client Service
belongs to software Atheros Configuration Service (ACS) or Atheros Configuration Service or ACU Configuration Service or Belkin Wireless Utility or Agnitum Outpost Firewall Pro or NETGEAR WPN311 Wireless Adapter or D-Link Wireless G WNA-1330 or Outpost Firewall (version 2009) or Agnitum Outpost Security
by Atheros or Agnitum (www.agnitum.com) or NETGEAR (www.netgear.com) or Belkin (www.belkin.com) or SMC or TRENDnet or OEM (www.oem.com).
Description: Acs.exe is not essential for the Windows OS and causes relatively few problems. The acs.exe file is located in the C:\Windows\System32 folder or sometimes in a subfolder of C:\Windows.
Known file sizes on Windows 8/7/XP are 36,864 bytes (66% of all occurrences), 364,629 bytes and 24 more variants.
There is no information about the author of the file. The program is not visible. The file is not a Windows core file. Acs.exe is an unknown file in the Windows folder. Acs.exe is able to hide itself. Therefore the technical security rating is 71% dangerous, however you should also read the user reviews.
You have the option to do the following:
1) uninstall Outpost Firewall or D-Link RangeBooster from your computer using the Control Panel applet "Add/Remove programs"
2) contact www.agnitum.com Customer Service 
3) search for an update  on the vendor’s website.
Recommended: Identify acs.exe related errors
Important: Some malware camouflages itself as acs.exe. Therefore, you should check the acs.exe process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.
A clean and tidy computer is the key requirement for avoiding problems with acs. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.
Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off doing a repair of your installation, or in the case of Windows 8, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.
To help you analyze the acs.exe process on your computer, the following programs have proven to be helpful: Security Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.