Rapi.
dll is an important component concerning the "Mobile Device Remote Application Programming Interface" (RAPI) function.
Specifically, the file is used to process the "ActiveSync" application in your Windows operating system.
ActiveSync is an important program in Windows.
Microsoft specifically designed the program to help maintain the files, settings and setup options in different devices attached to Windows.
The file is most useful when the system goes into a "sync mode".
Nonetheless, despite the functionality of the rapi.
dll file in the system, there are cases wherein it may suffer from problems and cause a number of errors.
When this happens, the system needs to be fixed as a matter of urgency.
There are several ways to solve such problems.
The succeeding discussion provides a step by step guide on how to do so.
It's important for users to understand that these steps should be followed strictly to ensure that no further complications will ensue.
When the rapi.
dll file becomes faulty and the computer is encountering errors because of it, the following messages are shown:

• "rapi.
  dll Not Found"
• "This application failed to start because rapi.
  dll was not found.
  Re-installing the application may fix this problem.
  "
• "Cannot find rapi.
  dll"
• "The file rapi.
  dll is missing.
  "
• "Cannot start Mobile Device Remote API.
  A required component is missing: rapi.
  dll.
  Please install the application again.
  "

Each type of error may be addressed with a certain type of troubleshooting method.
Nonetheless, it's recommended that the Windows system used be upgraded first of all.
Making sure your Windows system is updated can help lessen the chances of any errors occurring.
Other solutions include re-registering the file and cleaning the computer's registry.
Each troubleshooting method is discussed in this guide.
How To Fix Rapi.
dll Errors Windows Update Since the rapi.
dll file is a Windows component, the most effective method to fix problems related to it is to update the system.
There are two ways to update the Windows system.
One would be to go to Microsoft's Update Website and download the latest updates provided.
Install the downloaded upgrades and then restart the computer.
Another method would be to use the "Windows Update" function in the computer.
To do this, go to Start and then select All Programs.
Go to Windows Update and download the necessary upgrades by following the instructions it provides.
Install the updates and then restart the computer.
Downloading the updates should help refresh the settings and files needed to support the system.
It can also help overwrite damaged or corrupted components.
Re-Registering the File and Cleaning Registry Another cause of errors related to the rapi.
dll file is when the file accidentally becomes "un-registered" in the system.
Before re-registering the file, it needs to be located first.
To do this, go to Start and then select Search.
Choose All Files & Folders and then type in "rapi.
dll" in the search box.
Copy the file to this location: C:\Windows\System32 folder.
Move the file to re-register it.
Afterwards, go to Start once more and choose Run.
Type "cmd" and then press the Enter key.
Type regsvr32 -u rapi.
dll, press Enter and then type regsvr32 rapi.
dll and press Enter once more.
This should complete the re-registration process.
Cleaning the registry will also help eliminate problematic components, and indeed it is often a much simpler way of doing this.
The "registry" is a central database of all Windows PCs, which stores the information & settings that your computer uses to run.
Inside this database, 100's of DLL fiile locations are stored.
If any of these files becomes damaged / corrupted, then the registry is likely to blame.
In order to fix this, you should use a registry cleaner to fix any of the errors that your system may have inside this part of your PC.