[Windows 10 Mobile] jmattick:
Someone please tell me I'm doing something in the wrong order or help me understand why I can't get anywhere.

2 nights ago, I buy the Lumia 640 from Walmart as they were clearancing them out for $32.

I come home, and install the Insider Preview app and choose the Fast Track. Now I'm on .15184.

I come to XDA and see this thread. I download the tools in the proper order, install WPV XAP Deployer 2.0. Turn on Developer Tools, and move over the Root Tool xap. It moves successfully. I open and it gives me the option to Jailbreak Lumia. I click it. I then click "Interop + Capability Unlock and receive "SUCCESS :) You are done!". I then choose Unlock Win 10 Capabilities and again "SUCCESS :) You are done!).

I slip out of Root Tool and use WPV XAP Deployer 2.0 to try to deploy CustomPFD. I get an error "0x81030120" - Googling that doesn't really get me anywhere. I then try to deploy ADBlocker, same error, "0x81030120". I even tried WPTweaker, but this time I get a different message; "This package could not be registered."

It was at that point that I assumed the Jailbreak didn't work.

So I did the "Custom" using the vcREG v1.0 built into the Root Tool. Chose "HKEY_LOCAL_MACHINE", chose "DWORD", typed the path "SOFTWARE\Microsoft\DeviceReg\Install", typed the Key "MaxUnsignedApp" and typed the value as "7FFFFFF" then pressed Write. No errors YAY!

Then I pressed Read.

The Value given to me is 00000014, which is a Binary String, not a DWORD if I'm not mistaken.

Is there a step where I did something wrong here? Everytime I try to write the registry key as a DWORD used 7FFFFFFF, it goes through according to vcREG as such. But when I read it, a binary response.

My assumption is that RootTool isn't working, except it is the ONLY xap that could be transferred to the device. Any pointers? I know Windows and therefore the Registry well. I own a Surface Pro 3, but before that I owned a Surface RT which is what this is reminding me of.

Do I need to go back to Lumia Denim to start the Interop unlock? But if I do that, won't it be overwritten since we don't have SYSTEM access yet and the Windows 10 Upgrade pretty much will undo said progress?

I'm at a standstill. My next step is simply installing Visual Studio as much as I hate to and trying to use it to deploy xap's, because I don't want to go to all that trouble just to be standing right back here.

It took a few hours of Visual Studio to install before I started trying different ways because I was becoming annoyed with the size Visual Studio was, along with the dedication of standing by to press OKAY for this or restart for that.

My solution was finding the right vcREG to deploy. RootTool.xap did not work. The vcREG built into RootTool.xap did not work. Most of the vcREG deployments did not work, despite saying they were for W10.

It took finding vcREG_1_5_W10M.xap before it would deploy to my phone, and then I had access to the templates; first choosing Restore NDTKsvc for all Lumias except 950/XL, waiting two to three minutes, rebooting, and then choosing Live Interop/Capability Unlock and Live Full FS Access and then rebooting.

From there, I could deploy everything (CustomPFD, Adblocker), but not WPTweaker as it said there was an issue with the packaging and being registered.

Just a heads up for anyone who runs into this and doesn't want to go to all the trouble of sideloading vcREG fastforwarding the clock 100 years and messing with it being disguised as MixRadio.