Hmm.... didn't mean that, but so many ppl seem to be having a hard time with this lately, it's not even funny.

IDK how it is so hard... the Installer has been tested by

of us, with no problems, and then I hear of ppl having problems & it sounds like they used some voodoo mix of installing FS1, ST, FS2, manually installing some MVPs/ mods, (who knows where to!), and finally running Turey's Installer?? Anyways, I will continue to try to figure out what the problems are for everyone, but this is the basic low down of how to install:
(Note you could just use the walkthrough in my siggy

)
1) Uninstall FS2. (Unless you have not modified FS2 in any way besides upgrading to 1.20)
2) Install FS2 if you have it (do a full install).
3) Copy the FS1 & FS2 .MVEs, if you have the FS1 and/or the FS2 discs, into their appropriate FS2 directories, see my walkthrough.
4) Install using Turey's Installer, using the same directory as FS2 was installed to!
5) As Cobra said, Make sure FSPort is selected in Turey's Installer... as well as all the rest of the mods (at least, that's what I would do.)
6) If you want the original FS1 + ST, ie, no SCP upgrades... you already have this via FSPort, but if you want the unmodified version, then install FS1 to C:\Games\FreeSpace or another directory, then install Silent Threat into the FS1 folder, as Cobra said; but take care that you DO NOT INSTALL RETAIL FS1 OR RETAIL SILENT THREAT INTO THE FS2 FOLDER!!!