I want to install applications not originating from Marken in HTC Aria

[marfonline]

I want to install applications not originating from Marken in HTC Aria

 

[Dark Wizard Matoya]

If you have an Aria then your on AT&T, and AT&T doesn't like installing non market apps. If you can't just go into your settings and check "install from unknown sources" you could always try the Sideload Wonder Machine.