File Extension VXD
File extension VXD is used to identify virtual device driver files stored on Windows systems. These forms of files are installed on Windows based computers either through the OS or third party software installation. VXD are often referred to as Value-added Driver and are normally found only on Windows systems regardless of the OS version.
Virtual device drivers or VXD files are actually complementary "helper files" referenced by an application's executable. An application's main executable accesses the information stored within VXD files. The information is then used to launch the entire application correctly and provide support for the rest of its intended functions. However, not all executables (*.exe files) of an application require the use of virtual device drivers. There are plenty of applications that do not require the use of such file types since they do not interact directly with the system's virtual files.
Earlier operating systems by Microsoft like Windows 95, Windows 98, and Windows ME were known to contain and use VXD files as part of their startup process. In Windows 98, an error involving the VMM32.VXD during system startup is mostly encountered when the System.ini is modified as a result from installing certain hardware's device driver. This error can cause a computer to restart indefinitely unless addressed with the right solution. A similar issue can also be experienced when a computer's main system files are corrupted or downgraded from Windows XP back to Windows 98 or ME.
Like any other uncommon files, a user may try to open the file through the use of binary applications like Notepad for curiosity. This action is strongly discouraged by software makers since any alteration done on such file can cause undetermined response from the application. It is advisable not to touch any content written on VXD files.
On some systems upgraded to run Microsoft Virtual Machine support for Java or those that has Java installed, a VXD file can be found. The javasup.vxd is automatically installed on the system and can be seen at through the system's root. This file is essential for the system and must not be altered.
There are also other applications that are using VXD files as part of their package. Symantec, a renowned anti-virus software maker, has several VXD files installed on the host computer. Most of the files are used to contain virus and definition updates.