When you install Acrobat or Adobe Reader 8.1 or later on Windows, you see the following error message and the installation fails:

Error 1935. An error occurred during the installation of assembly
"Microsoft.VC80.CRT, version = "8.0.50727.163", type = "win32", publicKeytoken = "1fc8b3b9a1e18e3b". processorAchitecure = "x86


Solution 1: Clear the transaction log.

If you receive a 1935 error when you try to install Acrobat or Reader, the Windows file system transaction log has become corrupted. The Windows file system uses the log to recover when a file error occurs. To correct this install error, clear the log.

  1. Open an Administrator command prompt: Right-click Start > All Programs > Accessories > Command Prompt and select Run As Administrator. Click Allow for the elevation prompt
  2. In the command prompt, type the command below:

    fsutil resource setautoreset true C:\

    The line above assumes that C: is the drive in which Vista is installed. If it is installed on another drive like D:, change the drive letter appropriately.
  3. Restart the system.
  4. Install Acrobat or Adobe Reader again.

Solution 2: Disable antispyware and antivirus software or remove adware or spyware from your computer and then install Acrobat or Adobe Reader.

  1. Disable the following applications or types of applications, following any instructions provided by such software:
    • Disable Lavasoft Ad-Watch, Ad-Aware, or similar detection software before installation.
    • Disable WebRoot Spy Sweeper.
  2. Install Acrobat or Adobe Reader again.

Solution 3: Remove adware and then install Acrobat or Adobe Reader.

A certain type of adware running on the system can cause 1935 errors.

  1. Start the Task Manager.
  2. Look at the Processes tab. Look for a  process named wtoolsa.exe.
  3. If this process is running, then you remove this adware.
  4. Install Acrobat or Adobe Reader again.


Additional information

A 1935 error is one of the most common problems that can prevent you from being installing application that uses the Microsoft Windows Installer MSIAssembly and MSIAssemblyName tables. In general, this error means that Microsoft Windows Installer encountered an error while trying to install assemblies to the Global Assembly Cache (GAC) or the Win32 GAC (WinSxS). This error is considered fatal and causes setup to fail and initiate rollback.

Various circumstances cause the 1935 error:

  • Another application deletes the file while an Adobe application tries to open this file.
  • Some driver in the file system stack intercepts a CreateFile/ReadFile (and so on) and translates the error code to "file not found."