Intro: Installing this on Windows 10 is not specifically intuitive, so I am going to try and go through this step by step. As far as I know this will not work with a 32 bit version of Windows, but if I'm mistaken, please let me know if you have successfully installed this using a 32 bit version of Windows. The process for installing this on Windows 8 should be roughly the same, though I don't have a unit with Windows 8 installed to test this on. Windows 7 x64 works the same as Windows 10, but you are not required to disable driver signing. This is simply a collection of information I used to install OpenDingux on my own unit. I own nothing, and the risk is entirely yours.
Edit (5-17-19) More hardware versions are now supported with the current version of OpenDingux, and installing from Windows should be reasonably painless. I have upgraded the guide slightly to reflect the update.
Firstly, Driver Signature Enforcement must first be disabled on Windows.
1. On your keyboard, press and hold Shift, then click the Restart button.
2. Select "Troubleshoot"
3. Select "Advanced Options"
4. Select "Startup Settings"
5. Select "Restart"
At this point your computer will restart again, and bring you to a screen with several options. Once this occurs, press "7" to indicate the option for "Disable Driver Signature Enforcement" If pressing "7" does not select this, then try "F7" instead.
Your computer should now start normally. From here we need to install the driver for your RS-90.
1. Click the "Windows drivers download" from Pcercuei's website. (zcrc.me)
2. Download, and then extract "rs90-jzboot-drivers-win.zip"
3. Open your device manager on Windows. (In the bottom left beside the start menu simply type in "Device Manager" and click on the option with the words "Control Panel" underneath.
4. Now plug your RS-90 unit into your computer with the RS-90 powered off.
5. Power the RS-90 on while holding the "A" button to get the unit into the USB boot mode.
6. The Device Manager you opened should now pop up with a device called "JZ4750 USB Boot Device."
7. Right Click on the JZ4750 USB Boot Device, and click "Update Driver" followed by "Browse My Computer for Driver Software."
8. At this point, select the folder you unzipped from "rs90-jzboot-drivers-win.zip" making sure that the "include subfolders" box is checked. This will pop a dialogue warning to make sure that you want to install the driver. Select to install the driver anyways.
9. Once your driver has successfully installed make sure you have the "Flasher tool" from pcercuei's website.
10. Extract the flasher tool, and run the flash ".bat" file At this point follow the prompts to finish the installation. (This will be 1 of 2 files depending on your hardware revision. If you are unaware of your hardware revision start with "flash_v21.bat." If this fails, or if you are on a revision 3.0 unit, use "flash_v30.bat" instead.
11. Once this is done you can use a "fat32" formatted micro sd card to store your roms or additional files.
12. At this point you can put "OPK" files for the RS-90 in the app folder internally, and they will appear on the unit ready to use. (Please note OPK files from other systems will not work. They must be compiled for the RS-90.) FTP or SCP can be used to add files directly to the system. See pcercuei's website for further instructions on that.