I had to disable antivirus while I installed it and every once in a while I find a miner application file in my antivirus' quarantine and have to restore and add an exception to them. Unzipping the file with the bins it downloads when you first run NiceHash also hangs in the last 99% sometimes because it tries to overwrite a restored file or something that you don't have permission to for some unknown reason. You can try to install it again in a different place or delete the bin folder in safe mode and unzip the bins.zip yourself without nicehash running.