Quick Guide:
1) Browse to Your Conquer Folder (By Default C:\Program Files\Conquer 1.0)
2) Browse to the INI Folder inside the Conquer 1.0 Folder
3) Find StrRes.ini
4) Right click it, select Open With, uncheck "Always use this program to open this type of file" and select notepad. Press Ok.
5) Press CTRL/STRG + F or Edit -> Find.
6) Find the word "English" with that exact capitalization. I use Conquer 1.0, so the line with "English" was: 10426=English.
7) Change the word "English" to "english" by de-capitalizing the E. Leave everything after and before the E starting the word "English" as is.
8) Go To File -> Save.
9) Close all Conquers (Folders and StrRes.ini also for a tiny boost) and as much as is not needed to be able to run as many clients as needed.
10) Run Play.Exe or your conquer Shortcut (Just Conquer.exe if you bypass patch) and load Conquer as many times as you need clients.
11) Enjoy.