# CUDAQ[] returns False in version 9 while True in version 8

CUDA works in version 8 but not in version 9. Is there a way to fix the problem in version 9? I've installed the latest CUDA from the official website https://developer.nvidia.com/cuda-downloads

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I think you might have to force reinstall it... I had a similar issue when v9 first came out (I don't exactly recall what I did) – R. M. May 19 '13 at 1:47
This has happened to me. Try this in v9: CUDAResourcesUninstall[]; CUDAResourcesInstall[]. The download will take some time. – Szabolcs May 19 '13 at 2:38
@Szabolcs it works! Thanks so much! – xslittlegrass May 19 '13 at 17:01

This may happen because the CUDA resources downloaded are for version 8 and are not compatible with version 9. The problem can be fixed by re-installing them. To do this, evaluate the following in version 9:

Needs["CUDALink"]

CUDAResourcesUninstall[]
CUDAResourcesInstall[]
`