When I will finish my 180 days activation period is there something I could do to extend it but re-install windows ?
You can check by typing this on command prompt : slmgr /xpr There's no need to reinstall, just extend it just like when you activated it
180 KMS activated with a tool called AviiNL's Windows 8 KMS Activation Tool. I've tried to change the date and re run it but it can't activate anymore. Could be because of the wrong date ?
I think the only way to go is to wait until the period ends and try to activate again. Thanks everybody