Here's how I installed it on my 64bit Win8.1 machine (now upgraded to Win10, so should be similar/the same procedure). My signature has my system spec. None of this may be necessary if you're on 32bit (apart from step 4).
1. Copy CD-ROM contents to folder on PC
2. Copy setup32.exe from Is3Engine.zip to the INSTALL sub-folder (from http://toastytech.com/files/setup.html)
3. Run setup32.exe to install
4. Install 1.21 patch (Google for it)
5. Update registry strings in HKEY_LOCAL_MACHINE/SOFTWARE/Wow6432Node/LucasArts Entertainment Company LLC/Rogue Squadron/v1.0/ - change Analyze Path to CD drive (e.g E:\INSTALL\SysCheck.exe), change CD Path (e.g. E:), change Source Dir CD-ROM drive letter (e.g. E:\), Source Path to CD-ROM drive letter without the slash (e.g. E:)
NOTE: Game will crash after each level in Glide mode, just reload it (I haven't tested with newer Glide wrappers, things may have improved!).
Alternatively there's other fix guides like this one: http://www.play-old-pc-games.com/2014/10/01/s … rogue-squadron/
My PC spec: Win10 64bit, i7-4970K (not overclocked), KFA2 GeForce RTX 2070 SUPER, Creative Soundblaster ZXr, 16GB RAM, Asus Z97-A motherboard, NZXT 410 case, ROG Swift GSYNC monitor