Could anyone tell me how I should place these two scenery addons in FSX (Priority). And also how to install Service Packs. For example I have a clean hard without SP1 or SP2. Now I have FSX Acceleration which is SP2 do I just install this after the regular installation of FSX or after a regular installation of FSX do I install SP1 then Acceleration?

If you already have just the base FSX installed, run it at least once so that it creates some configuation files it needs, then shut it down and install Acceleration. Acceleration includes both SP1 and SP2 content.As for how to layer UTX landclass with another 3rd-party landclass like X-Class, this is described in detail in the UTX manual under the "Using other Landclass Products" part of the "Ordering of Ultimate Terrain X Layers" section. Essentially after installing UTX and the X-Class make sure that you move the X-Class landclass so that the FSX Scenery Library order for the UTX and X-Class landclass layers looks something like- UT Landclass - Custom- UT Landclass - Urban- X-Class landclass- UT Landclass - Vegetation.If you need more help, go to the Ultimate Terrain product support forum over at SimForums here.Jeff