cudart32_80.dll means you need 32-bit version CUDA 8.x.By any chance, do you intentionally download older version of BitCrack since latest BitCrack uses CUDA 10.1 ?
He just needs to unzip the CUDA 9.2 installer using a tool like 7-zip, which he can get from
https://developer.nvidia.com/cuda-92-download-archive?target_os=Windows&target_arch=x86_64, and then locate cudart32_80.dll, extract it and put it in the same folder as bitcrack.
There is no need to install the CUDA sdk itself, only that single dll is needed. Just get the local installer though, not the network installer.
I didn't know such thing is possible, usually i would install multiple CUDA version at once.