There must be windows CE and .Net framework on your mobile.
After that, use your mobile trader link with the extension .msi to download the mobile trader.
After you connect the mobile to the computer and download the file run it, an installer to the pc will run after that, it will be connected to the mobile installer automatically, and after the wizard ends the Mobile Trader will be installed successfully.

Another way is to use your mobile trader link with the extension zip to download the mobile trader.
Then just unzip the files and copy them one by one to your mobile, one of them will install the Mobile Trader, and that one will be compatible with your phone processor

Note that both ways require the .Net Compact Framework to be installed at your mobile; if you do not have it you can download it from these links.
http://www.hybridsolutions.com/netcfsetup.msi
http://www.hybridsolutions.com/netcfsetup.zip