Ok, for me the Torcs trackgen is in C:\Program Files\torcs
And the SD trackgen is in C:\Program Files\speed-dreams-2.0.0\bin
Yours should be similar depending on which Windows version you have. Your version of SD is probably newer than mine also.
The Torcs trackgen is just named trackgen and the SD trackgen is named sd2-trackgen.
Just open the command prompt in Windows and type in CD "C:\Program Files\torcs" or CD "C:\Program Files\speed-dreams-2.x.x\bin" if you want to use the SD trackgen. Keep the quote marks or it won't work. And remember to replace the x.x with the version of Speed Dreams you have.
Then type in trackgen if you are in the Torcs directory or sd2-trackgen if you are in the Speed Dreams directory and it will tell you how to use it.
Hope that helps.