Just to keep you up to date. My attempt to install ARsoft Ram Disk has caused so much trouble I have uninstalled it . Alan & David have mailed a lot of information which I will try and digest.
As a matter of interest this attempt with Ram Disk has thoroughly up set the Technisat programme as I am left with a red T when trying to run Metop and no data coming in. When I switch back to running MSG DM the pink T returns and all runs correctly as it has done for years. There appears to be no change in the received.ini or else where and the settings are as you recommended.