Do not use random YouTube links. The safest repository is Revora Network or GameCopyWorld (historical archive). Look for the file named Gen_v1.8_PLUS_6_TRN.rar .
The internet is littered with dead links and sites promising a "Command And Conquer Generals 1.8 Trainer WORK" that turn out to be malware. To find a legitimate, working file, you should stick to reputable modding and cheating communities. Command And Conquer Generals 1.8 Trainer WORK
If you search YouTube or cheat forums, you will find dozens of links. Most claim to work for version 1.8, but here is what actually happens: Do not use random YouTube links
: Instant recruiting and building construction. Command & Conquer: Generals Cheats and Trainer Command And Conquer Generals 1.8 Trainer WORK
If you are having trouble running the game at all on modern hardware, use GenPatcher