He/SHe may be launching the 64 bit version instead of the 32 bit.... which I did the first time I tried this application....
Go to the install directory of WOW and change the 64 to some other name.... there are many other options
here is a link that is 2 years old but may give you way more info about this https://eu.battle.net/forums/en/wow/topic/15162514290
Also I like to be a smartass http://lmgtfy.com/?q=how+to+run+32+bit+wow