1. Download this: Go to https://github.com/ethereum/go-ethereum and go to "Automated Development Builds" farther down the page. Download the windows one and extract it to where you wish. This is the Go Ethereum (geth) platform
2. Download this: https://build.ethdev.com/builds/Windows%20C%2B%2B%20develop%20branch/Ethereum%20%28%2B%2B%29-win64-latest.exe Download the bottom file, as it contains the only miner confirmed to work in Windows.
This is the C++ ethereum platform. This contains the miner.
3. Then download this and remember where it is. Easiest to put it in the same folder you save the above automated geth.exe; http://jev.io/genesis_block.json (just right click and save link as in the geth folder (wherever you extract it))
4. Once you've done the above steps, open a cmd terminal in admin mode (just to be safe) and navigate to the geth directory.
5. Use the command "geth account new" This will generate an Ethereum address for you.
6. Use the command "geth --genesis genesis_block.json" (If you saved it in the same folder that geth.exe is in. If you didn't you will have to specify the directory path). This is to synchronize with the blockchain. At first large numbers of imported blocks will appear (128, 256 etc.) once it decreases back to 0 or 1, close the process (ctrl+C).
7. To ensure mined blocks go to your coinbase then use the command "geth --etherbase <your address> --rpc console"
8. Open another cmd terminal in admin mode. Navigate to ethereum (++) 0.9.40\release
9. use command "ethminer -G --opencl-device 0 (if one card, or the command for however many GPUs you intend to mine with)
If you get an 'insufficient memory error' but know your GPU has enough memory (2GB+) use this command instead:
ethminer --no-precompute -G --opencl-device 0 --opencl-platform 1