First things first. Before downloading and installing the game client, make sure that your a/v utility and your firewall are
temporarily disabled. Windows will grouse about that, but ignore it.
Go into your designated download folder (usually in C:\Users\{accountname}\ for Vista and Windows 7; I use a completely different folder and location for it, out of habit) and make sure that you don't have any old copies of the RoM client(s) squirreled away. Delete them. Same for old manual patches.
Download the client. Go have lunch or run around the block elebenty-seben times.
When it's finished downloading, install it.
When the installation is finished, run the game client (Runes of Magic.exe; there should be a RoM icon/shortcut on your Desktop.) Allow the updater to do its job and update the client. Go have supper or run around the block sebenty-eleben times.
The current client update level is 5.0.3.2575en.
Should you need to manually patch your installation, go here:
http://forum.us.runesofmagic.com/showthread.php?t=31461
Read Tigsman's instructions on downloading the patche(s) you need, where to copy them (main RoM game installation folder), and the order in which the patches need to be installed.
When finished, re-enable your a/v and firewall programs.
