Software Deployment

when i try to install anything that is a MSI package it gives me a error that says "The system cannot open the device or file specified." then says retry or cancel... Retry just keeps on popping up the same message. When i click cancel it says "Internal Error 2755. 110, (directory of the setup file iam installing) C:\documents and settings\admin\desktop\netcfsetupv2.msi"
i read a couple of forums that said i need to right click on the setup and advance and click on the encrypt box, but i have xp home which grays that selection. can anyone help me please!!