Avoid "exe downloader" sites that ask you to install a "download manager." The file you need is extremely small—usually less than 1 KB or a simple .reg (registry) file.
To download and use the IGI 1 All Mission Unlock File, follow these steps: Igi 1 All Mission Unlock File Download
The Appeal and Impact of Mission Unlockers in Project I.G.I. Project I.G.I. Avoid "exe downloader" sites that ask you to
Always scan any downloaded file with VirusTotal before opening it. A legitimate unlock file should have 0/60 detections. Always scan any downloaded file with VirusTotal before
[HKEY_CURRENT_USER\Software\Innerloop\Project IGI\Settings] "LatestMission"=dword:0000000e
If you have never played IGI 1 before, I recommend playing the first three missions legitimately to learn the mechanics (leaning, peeking, distance shooting). After that, unlock the rest. There is no shame in skipping the frustration of Mission 11 ( The Monastery ), which is famously broken due to invisible snipers.
: Find a reputable source for the "IGI 1 Mission Unlock" or "100% Save Game" file. Trusted gaming communities like PC Savegames or SaveGame.Pro often host these .qvm files.