I was wondering if any one can help me with the installer I have for the program I would like to know if I ran the USB to Serial Driver install would it just install over the top of the driver if already installed and create it if not installed or would it be better to check the usbser.sys for the relevant file?
You don't need to worry about usbser.sys at all.
Just install your INF file.
Make up an INF file, following this guideline.
How to use or to reference the Usbser.sys driver from universal serial bus (USB) modem .inf files
http://support.microsoft.com/kb/837637/en-usThe point of above KB is,
[DDInstall.NT]
include=mdmcpq.inf
CopyFiles=FakeModemCopyFileSection
The right version of usbser.sys for the target PC is stored on somewhere specific to the PC setup. It may be in DriverStore, or in a .CAB file under I386 folder, or included in its install CD. The location of usbser.sys on the setup is written in FakeModemCopyFileSection of mdmcpq.inf, which is customized for the target PC at primary OS installation. Using above lines in INF, the install engine on OS automatically finds the usbser.sys, and copies it to the right place (driver folder).
Therefore, you should not distribute usbser.sys on your install package.
To (pre-)install your INF, DPInst.exe is handy.
This utility is included in WDK (C:\WINDDK\7600.16385.1\redist\DIFx\dpinst)
Windows Driver Kit Version 7.1.0
http://www.microsoft.com/en-us/download/details.aspx?id=11800Tsuneo