WinRAR 3.50 Beta 5 x64 Shell Extensions DO WORK..

Update: Extended64.com is happy to provide you with an easy patcher that totally obsoletes the following method.  You can find it, here.

Just like everyone else, I got real excited when I saw this in the WinRAR changelog:

1. WinRAR is able to integrate to Windows context menus also on Windows x64 systems.

I immediately downloaded and installed the latest version of WinRAR.  After setup was complete, I hopped into an x64 Explorer Window, right clicked on a folder.... and I was horribly disapointed.  So, I decided to go on a little investigating work.  First thing I noticed is that the GUID for the new 64-bit Shell Extension is: {B41DB860-64E4-11D2-9906-E49FADC173CA} and it lives in %Install Path%\rarext64.dll.  After 20 minutes of poking around the registry, I noticed that "HKEY_CLASSES_ROOT\CLSID\{B41DB860-64E4-11D2-9906-E49FADC173CA}" was missing.  Copy-Paste the following into a .reg file and merge it into your registry (adjust the path as required):

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\CLSID\{B41DB860-64E4-11D2-9906-E49FADC173CA}]
@="WinRAR"

[HKEY_CLASSES_ROOT\CLSID\{B41DB860-64E4-11D2-9906-E49FADC173CA}\InProcServer32]
@="C:\\Program Files (x86)\\WinRAR\\rarext64.dll"
"ThreadingModel"="Apartment"

After I made that change, WinRAR Shell Extensions still didn't work.  I fired up PE Explorer, and looked at the dissasembly of RarExtLoader.exe.  I quickly noticed that it had a hardcoded path to the shell extension - "D:\Projects\WinRAR\RarExt\rarext.dll". 

With that said, I closed PE Explorer, fired up my favorite Hex Editor (XVI32).  In XVI32, I opened RarExtLoader.exe, and did a text string replace (Search -> Replace), finding D:\ and replacing it with C:\.  When the replace was finished, I went to File -> Save, and then closed XVI32.

I then created a C:\Projects\WinRAR\RarExt\ folder, and copied the contents of my entire WinRAR installation to it.

After copying my files, the 64-bit Explorer WinRAR Shell extension worked.

So, it's not pretty, but it's possible.  I'm sure the next beta version of WinRAR will improve on this aspect.