Summary
If you want, I can:
Steam (Official): Right-click the game in your library, select Properties > Installed Files, and click Verify integrity of game files. This will automatically detect and redownload the missing iw4sp.exe. Iw4sp.exe Download
Always scan any downloaded executable with VirusTotal before running it. Informative review — iw4sp
handles high frame rates and resolution scaling remarkably well, though you might need minor community patches for ultra-widescreen support. The "Download" Dilemma: Risks & Red Flags select Properties > Installed Files