The 1935 Error message is generated by the Windows Installer when it is unable to access a specific file, folder, or area of the system's registry for some reason. Normally, this error is generated if the user does not have full administrative rights to the entire computer (including all files, folders, and areas of the Windows Registry).

In this situation the 1935 error appears to be related to some recent updates released by Microsoft for the Microsoft XML Parser. One of these updates is partially installed on the computer and the Windows Installer is unable to verify and provide the proper version information to our Installer Package. This failure generates the 1935 error message when our Installer is unable to determine the version of MSXML installed on the computer.

Take the following steps to manually update the Microsoft XML files on your computer in order to resolve the error:

First, download the MSXML4 Sp2 update by clicking the link to msxml.msi at the bottom of the following Microsoft Article and saving the file to the Desktop of the computer:

MSXML 4.0 Service Pack 2 (Microsoft XML Core Services)

Once the update file has been downloaded to the Desktop of your computer take the following steps to remove the partial installation of the software from your computer:

Remove the current installation (if present)

1. Close any open programs.
2. Click Start, Settings, Control Panel then
3. Double click Add/Remove Programs.
4. Select the program  (if present) and click Remove.
5. Click Application Manager (or Palo Alto Software's Application Manager if present) then click Remove.
6. Once finished, restart the computer.

Now, install the updates and software in a clean boot of the operating system:

How to perform a minimal boot in Windows XP

Note: You must be logged on as an administrator or a member of the Administrators group to follow these steps. If your computer is connected to a network, network policy settings may also prevent you from follow these steps.

1. Click Start, click Run, type msconfig in the Open box, and then click OK.
2. On the General tab, click Diagnostic Startup. 
3. On the Services tab, click the word Service at the top of the list to alphabatize the services, then locate and check the box for Windows Installer.
4. Click OK, and then click Restart to restart your computer. 
5. Once the computer has restarted, click OK to the message about the System Configuration Utility and then close the System Configuration Utilty by clicking Cancel.

Once the computer has been restarted into a Clean Boot of the Operating System, take the following steps to install the MSXML Updates downloaded in the previous steps:

• Double click on the msxml.msi file which was downloaded from Microsoft's Article to install the Service Pack 2 update for the MSXML components of Windows.

If you encounter an error when attempting to install the MSXML SP2 update (msxml.msi) you may have to remove the previous versions of MSXML from the computer first. Take the following steps to use the Windows Installer (msiexec) to remove the previous versions (instructions from Microsoft's MSXML release notes):

To uninstall MSXML 4.0 SP1:

1. Click on Start then select Run and hit the Backspace key to delete the contents of the Open box.
2. Type or copy and paste the following into the Open box and click OK:
   
   msiexec /qn /x {35343FF7-939B-401A-87B3-FF90A5123D88}

To uninstall MSXML 4.0, run the following from a command prompt

1. Click on Start then select Run and hit the Backspace key to delete the contents of the Open box.
2. Type or copy and paste the following into the Open box and click OK:
   
   msiexec /qn /x {2AEBE10C-D819-4EBF-BC60-03BF2327D340}
   

Once both of the previous installations have been removed, use the msxml.msi file to install the MSXML 4 Sp2 updates.

• If the MSXML Service Pack update still fails to install, you would need to contact Microsoft's Technical support for assistance in completeting the installation of that MSXML update before proceeding to install our software.
• If the MSXML update installs normally, you should be able to restart the computer and then install your Palo Alto Software program on the computer in order to resolve the original problem which you encountered.

Once the installation has finished, return to the MSCONFIG utility and select the Normal Startup option, then reply to this message and let us know if either of these options allowed you to successfully install the software on this computer