Good luck with that. WP is all about a stable user experience. But if you insist, first you need to developer unlock, either by paying Microsoft $99/year for a Dev account (to post apps) or pay The Chevron Team $9 for the same unlock without the ability to offer apps in the Marketplace. Next you need to Interop unlock your phone (search XDA for that). Then you can find and install a reg editor, but accessibility is limited. Good luck with all that. Pre-mango, I made made one innocent change to the registry and and spent the next six hours resetting and rebuilding my phone from scratch. I am done with all that. Some simple Homebrew apps are ok. But everything else, no thank you.
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