UOSteam, formerly AssistUO, is also available on An Corp.
1. Download and install the Microsoft Visual C++ Package:
Microsoft Visual C++ Package
Note: it is possible that you already have that installed, in this case just ignore this first step
2. Download and install UOSteam:
UOSteam [126.96.36.199] Stable Version
3. Run UOSteam as administrator, type or select the server you want to play and click the "Start" button.