Environment variables go into the batch file you use to run the miner. There is a start.bat in the miner folder. Edit that and add your environment variables before you run the miner.
For example
setx GPU_FORCE_64BIT_PTR 0
setx GPU_MAX_HEAP_SIZE 100
setx GPU_USE_SYNC_OBJECTS 1
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_SINGLE_ALLOC_PERCENT 100
ZecMiner64.exe
Thanks for the quick reply. I have removed these from my windows environmental variables and added them to my batch file. Still crashing on start as before.
Also you mentioned the -ethi command isn't working. I believe that the command line can only handle a certain amount of variables. You have to use the config files (and why wouldn't you? I can't believe all the people that ignore them) if you have 3 or more commands on the command line. I think if you try the config files you'll find the -ethi 4 command will work. There should also be a config file in the root of your Claymore Zcash miner folder. There you can also find fun things like epools which is a config of your backup pools. (epools is left over naming scheme from his ethereum miner.)
I have moved all my commands to the config file as suggested and I'm still getting an error with the -ethi 4 command switch. The console reports "UNKNOWN OPTION -ethi" in red, then on the next line "UNKNOWN OPTION 4" also in red.
Any other suggestions would be much appreciated.
Thanks,