C:\Users[your user id]\AppData\Roaming\desirecore\desire.conf'
hi the path is wrong it should be your user id, if its admin then it should look like this
C:\Users\admin\AppData\Roaming\desirecore\desire.conf'

the desire.conf needs to be in the roaming location, but if its not in the roaming dir then you need to find where that may be. if you still can find the file you can use an app called every thing

http://www.voidtools.com/

this tool will index your entire hard drive and find the file you are wanting to find.