MSASCui.exe is a digitally signed file from Microsoft located in folder C:\Program Files\Windows Defender.
It is a component of Microsoft Windows Defender Antispyware. This file is responsible for performing spyware scans. It is already installed in Windows Vista operating system. MSASCui.exe becomes an error code when it is found in another path. It is categorized as a Windows runtime error.
Error CausesThe cause of MSASCui.exe error is triggered by:
The potential risks of MSASCui.exe error are:
When this file becomes an error, it will display messages like:
“This application has failed to start to run on Windows because MSASCUI.exe cannot be found.”
“Windows Defender cannot work properly and protect the Windows system effectively”
The message will keep popping up on your computer screen time and again.
When you experience an MSASCui.exe error on your PC, it is advisable to fix and repair it immediately before it causes serious damages to your system.
Here are some DIY quick solutions to repair MSASCui.exe error:
If the speed of your PC reduces significantly and you also see MSASCui.exe error message pop on your screen, then in this case it is advisable to uninstall the Windows Defender program from your PC.
To do so, follow these instructions:
If you find the MSASCui.exe file located in some other path, then this is an indication of a virus.
In this case, it is recommended to run an antivirus program on your PC to scan and delete all viruses.
If you don’t have an antivirus program already installed on your system, then you should download it. Once antivirus software is downloaded, simply run it to scan viruses and then click on delete to remove all the viruses on your system.
This will help you resolve the MSASCui.exe error caused by malware on your PC right away.

Error Causes
Error CausesError Code 48 is a device driver error code that users can encounter on any Windows 2000 operating system and later versions.
It occurs when the connected peripheral device cannot be run as the Windows operating system’s driver required to install the programs for peripheral devices has either been corrupted or is incompatible with the system.
It prompts the user with the following message on the screen:
The software for this device has been blocked from starting because it is known to have problems with Windows. Contact the hardware vendor for a new driver. (Code 48)
Error CausesLike most other Windows error codes, error code 48 is triggered by the following factors.
Identifying and removing the viruses in the system registry and in the connected devices is the easiest method to fix the corrupted registry files.
Viruses such as spyware and malware infect the registry entries and eat up the files that lead to incomplete or missing data. This creates problems for installing external devices as the driver required to install them is not complete.
You can also use system restore to eliminate the problem. Here is how you can use it:
By restoring the system via the last saved system checkpoint, you can obtain undamaged Windows system registry files that can help resolve the error code.
Since Error Code 48 is due to a missing or an out-of-date device driver, uninstalling and then reinstalling the device driver can help solve the error.
You can do this by firstly logging in as Administrator and opening Device Manager. Select the device that is causing the problem and double click it; make sure that the peripheral is connected properly to the PC.
Upon opening, click on the ‘Driver’ tab and then select ‘Update Driver’. Make sure to refer to the system documentation that you received with your PC or computer to check for the motherboard details and driver specifics.