Windows Defender stopping program from running

Choosing a good antivirus from a plethora of options on the market is easier said than done. Thankfully, Windows comes with an antivirus that is baked into the system called “Microsoft Defender”. And it's pretty good.

Over the years, Microsoft Defender has evolved from a basic antivirus program to one of the best threat protection systems in the industry. What’s more, you can make Microsoft Defender even better with DefenderUI.

What Is DefenderUI?

DefenderUI, as the name suggests, is a UI overlay over Microsoft Defender. It provides a handy GUI to configure different Defender options.

DefenderUI also unlocks many hidden and hard-to-find features, allowing you to tweak many aspects of Microsoft Defender. For instance, with DefenderUI you can exclude specific files and folders from Defender scans without digging through the Windows Settings app.

How to Use DefenderUI to Configure Microsoft Defender

To begin, download DefenderUI and install it. Once the app is up and running, launch the program.

Once you launch DefenderUI for the first time, you will be presented with different security profiles to choose from. For instance, if you want the most control over Microsoft Defender with access to almost all hidden features, choose Aggressive.

Otherwise, choose Recommended, as the profile offers many features above and beyond the default Defender configuration while remaining accessible to average users.

The Home Tab

The Home tab in the DefenderUI presents many default Microsoft Defender options. There are Realtime, Scan, Utility, and DefenderUI Settings.

In the Realtime section, you can:

• Disable/Enable Real-time protection to stop Defender from continuously running security in the background.
• Disable/Enable Cloud-delivered protection to keep Defender from using data to talk to Microsoft cloud servers to enhance real-time threat detection.
• Disable/Enable Windows Firewall. So, if you are annoyed with Windows Firewall pop-ups, unchecking this option will stop the Firewall from running.

Moving on, the Scan section allows you to run a quick scan, manually customize one, and perform an offline scan. You can also update and reset program signatures.

If you want to add exclusions to Defender to keep the antivirus from scanning certain folders or files, you can add one in the Utilities section by choosing an option from the Add exclusion dropdown menu.

Similarly, you can also manage Protection History settings including clearing and repairing the Defender Protection History.

Finally, in the DefenderUI Settings, you can change the language of DefenderUI, choose whether the program starts with Windows, and customize Dark mode appearance.

The Basic Features

The Basic tab is where more advanced DefenderUI features reside. You can fine-tune Window Defender protection mechanisms and customize privacy features from the General section. Additionally, you can also tweak how Defender notifications work.

Diving a little deeper into General settings, you can:

• Enable/Disable Network protection that keeps bad apps/viruses from affecting devices on your network.
• Enable/Disable Behavior monitoring, a feature that keeps tabs on programs installed on your computer.
• Enable/Disable Potentially Unwanted Apps (PUA) protection that, as the name suggests, stops malware by blocking potentially harmful programs.

Finally, you can also set Cloud protection level and Cloud check timeout to configure Block at first sight behavior. “Block at first sight” is a feature that blocks malware within seconds using cloud protection mechanisms.

Moving on to the Privacy section and here you can whether Defender submits a sample automatically to Microsoft for threat detection or gets user consent first. Leave this option enabled if privacy isn’t critical to your work.

If you are worried about unintended people messing around with virus and threat protection settings on your PC, you can check Hide virus and threat protection in Windows security and Hide threat history from non-administrators. Both these options are available in the Privacy section of the Basic tab.

Last but not the least, DefenderUI also allows you to change the notification behavior of Microsoft Defender. In the Notifications section, you can enable/disable notifications regarding threat warnings, scan results, and blocked files/activities.

The Advanced Features

One of the best things about DefenderUI is that the app gives you simple controls to tailor the Microsoft Defender options intended for advanced users.

First, you can tweak the Microsoft Defender’s scanning behavior by choosing which files/folders are scanned and which aren’t. For instance, unchecking the Scan email option under the Scan Options section will keep Defender from sifting through your emails.

Similarly, you can also stop Defender from scanning network files, scripts, removable drives, etc.

Secondly, the Advanced tab also offers settings to configure the performance and network impact Defender has on your PC. For example, if you turn off File hash computation, Defender will no longer computer hashes for every .exe file on your computer.

Hash computation is a taxing process, so it may tank system performance significantly. Disabling the setting can have a positive impact on the overall system responsiveness.

Low CPU priority has a similar effect on the system performance. You can also set Average CPU utilization while scanning and Signature update interval to further optimize the resource usage.

Finally, you can also set custom Defender behavior in case of a threat in the Threat Default Actions section. There are options to define the action taken by the Defender based on the threat level.

For instance, if Defender detects a “Low threat”, it blocks the file/script to stop it from running. This is Defender’s default behavior. You can change it by selecting one from the Low threat dropdown menu.

DefenderUI Makes Microsoft Defender Accessible… but It Can’t Resolve All of Its Issues

Although DefenderUI makes Microsoft Defender increasingly usable and its feature set more robust, there are issues that it can’t solve.

Microsoft Defender, like almost every Microsoft app, can become annoying to use even after you configure it extensively. In some cases, the app can enable itself after you disable it.

Fortunately, almost all such problems are relatively easy to fix.