ok, i think i dont need to open ports on my router. but do i have to install every single patch right from the first?
If you downloaded the latest Chapter V client files, there are only two patches to install. If you're using an older set of installation files (downloaded from one of the mirror sites that the EU Runes of Magic website lists), then all of the patches issued
after the version number of the client will have to be installed. I strongly recommend using the Chapter V installation files.
It's possible that your anti-virus utility is either deleting or locking out temporary files that are part of the uncompressed patch(es). Some of these utilities are over-aggressive and decide that filenames which include a "$" character are infected, and need to be deleted or quarantined. You can temporarily disable your a/v utility, install and patch the RoM client, then re-enable the utility. How you do that depends on the a/v client you're using. Look in the Windows task tray to find your a/v client, close or exit it, then install and patch. When you're finished, restart the computer to re-enable your a/v utility.
Hope this helps.