Need help running UE4

I have a triple boot computer with a linux, windows 8 ,windows 10 and a 500gb drive full so i cant install UE4 onto the windows 10 os so i tried running it from the windows 8 partition on windows 10 so ive started epic game launcher (i have acces to the windows 8 partition from windows 10) epic game launcher worked fine but when i go to the UE4 section its not showing my UE4 version. can someone help me fixing this please.