I have a similar Issue.
I bought a 8Gb AMD RX 480 gpu, i'm trying to install the driver but after the installer unpacks i get the Error 174.
The Website where i get redirected says it's because the Graphic card is Unsupported, it's funny cause if i try to use it to install the drivers for the integrated GPU, i have an AMD A8 6600k with a Radeon 8570D integrated GPU, which should not be supported, it woks fine.
i've been messing around the whole day, i used both the AMD Cleaned and DDU, i disabled the integrated card, but no such luck.
It's getting pretty boring.
I have a Windows 8.1 with
AMD A8 6600k with a Radeon 8570D integrated GPU
Sapphire's AMD RX 480 NITRO+ 8Gb
ASUS A88XM-A Motherboard
Having the same problem with my MSI's RX480 Gaming X 8GB, although it have a "continue" button and the installations completes okay everytime I try to install Crimson Software drivers I get that error :/
These are my rig specs:
AMD A4 5300 APU with a Radeon HD 7480D integrated GPU
MSI's AMD RX 480 Gaming X 8Gb
FM2-A75MA-P33 MS-7721 Motherboard
1000w Thermaltake PowerUnit