VDDT and TELSA install packs have not been updated since the Windows XP operating system. As a result, some extra steps need to be taken for more recent Windows operating systems.
WinHlp32 is the utility that displays older format Help files (with the .hlp file name extension). Starting with Windows Vista, this application is no longer automatically installed with Windows. To view *.hlp files on computers with Windows Vista or later operating systems, you will need to download and install WinHlp32 from the Microsoft Download Center. Once you have located the version you need for your operating system and have downloaded and installed WinHlp32, you can view *.hlp files for any application that uses *hlp files, including TELSA and VDDT. You should install WinHlp32 before attempting to install VDDT or TELSA.
Installation Security Settings
If your installation of VDDT or TELSA on a Microsoft Vista machine is not successful, one reason may be the inherent security settings of Vista/W7/W8. These settings are intended to prevent unauthorized changes from being made to your computer, but may also prevent the installation of some programs, even though you have administrative privileges. Follow the steps below to suspend the security settings so you can install VDDT and/or TELSA. When you have successfully installed and run the program(s), you should reinstate the default security settings as specified in the last step of these instructions.
On the Control Panel window, click on the User Accounts link. When you do this, click either on the people icon or on User Accounts; do not click on the Change account type link below User Accounts.
On the User Accounts window, click on the people icon as shown in the screen shot below. Do not click on any of the three links below the User Accounts link. This step opens a window that allows you to make changes to user account control.
Click on the Turn User Account Control on or off link.
Turn the Use User Account Control (UAC) feature off. To do this, left-click in the checkbox to remove the checkmark there, and click OK. Click through any subsequent screens to return to your desktop.
After you have installed VDDT and run it once, to ensure that all components are working properly, turn the UAC feature back on. To do this, repeat Steps 1-3 above. In Step 4, left-click in the UAC checkbox to enter a checkmark there; this will turn the feature back on. Click OK through any subsequent screens to return to your desktop.