WARNING: 
1) Install as  'Administrator'

2) Before installing PLC IDE 1.0.6 (or newer),
ensure that both PLC IDE 1.0.3 and
PLC IDE Tools 1.0.3 are uninstalled 
from Windows 
using the "Add or remove programs" tool. 

3) Delete the "T" folder located in 
C:\Users\<your username>\AppData\Local\T.