And are you trying to install the Acronis PXE server from section 3.7 page 29 of the Snap Deployment version 3 UG?
So is step 3 in the process where your having an issue?
3.7.1 Installation of Acronis PXE Server
To install Acronis PXE Server:
1. Run the Acronis Snap Deploy setup program
2. Click Install Acronis PXE Server
3. Follow the on screen Install Wizard instructions.
Why are you trying to install 3, when 4 has been out over a year has it not? I would suggest you call them if you are having issues using their product in your environment
if you just want some basic info about PXE and then from there links to more info - I would prob start here
Here is a walk thru on how to setup a generic pxe boot server