Sometimes, you might have the need to run on a version of TIDE that is not the most recent; then you might run into the problem of not being able to download the correct version of TiOS firmware to work with this particular version of TIDE. In fact, with every install of TIDE, the TiOS firmware for each platform are included.
In a typical installation, the location of the folder would be:
C:\Program Files (x86)\Tibbo\TIDE\Platforms\[Platform Name]\firmware
[Platform Name] is the name of your platform, for example, if you are working with TPS2(G2), the platform would be TPP2W(G2), if you are working with EM1206EV, the platform would be either EM1206 or EM1206W depending on if you are using WiFi.