If upgrading from version 1.0 you will have to remove the old version before installing the new version. Follow this procedure for removing it:

Uninstall the existing Technisoft Field Portal version 1.0.1

In IIS manager:

oDelete the TSConnect virtual directory

oRemove the Field Portal (or possibly named TSConnect) application pool

oDelete the folder: C:\inetpub\wwwroot\TSConnect

oDelete the folder: C:\Program Files (x86)\Technisoft\TSConnect

Install 1.1 or 2.X as normal