Dimension Pro is installed separately from X2, so not to worry there.
It sounds like you have X2 Producer Edition, which comes with Dimension Pro 1.5, along with all the other goodies.
If instead you purchased Dimension Pro separately, then you will either have its installer, or can download it again from your Cakewalk store account.
If you have your install files, Dimension Pro has its own installer.
If you do not have the install files, go to Cakewalk.com and log on, and in your store account, you will see the download links for your products, as well as your serial numbers and registration codes.
You can download Dimension Pro directly from there as well.
Dimension Pro will install by itself. PLEASE NOTE that some folks have reported integrity issues with downloaded files from the Cakewalk site, when their antivirus software is running when doing the downloads. This is not universally reported as being problematic - but I can tell you that I had corrupted download files on at least one occasion that I recall, and I thereafter ALWAYS temporarily suspend my antivirus software right before I click the download button from the store, for any Cakewalk products.
ALSO, installing and/or running a program for a user account that has admin privileges is a different thing than installing/running a program with the explicit Run As Administrator option set. Elevated privileges are granted with Run As Administrator for program execution, and I ALWAYS install programs with the Run As Administrator option set. These additional privileges are sometimes required for a program to install properly and/or to even run.
For instance, Pentagon seems to want these elevated privileges in order to work in Sonar, and Dimension Pro will not properly complete registration if it is not done while running with Run As Administrator set.
There are a couple of ways of setting the Run As Administrator option. 1st way - right-click on the program's launch icon or executable file, and click on Run As Administrator. This will set the Run As Administrator option for this execution only. 2nd way - right click on program launch icon or install program, click Properties, click Advanced, then check the Run As Administrator box, click OK, then click Apply, and if it tells you that you need administrative privileges to make this change, even if you are already an administrator, click OK. This method will permanently set the Run As Administrator option for that program's launch icon or executable file.
So, I recommend you:
1. Look for the install files. If you have them, Dimension Pro has 2 files, one is the executable installer, and the other is a zipped file of Dimension Pro expansion packs.
These 2 files are called:
04_Dimension_Pro_1_5_Setup.exe
04_Dimension_Pro_1.5_Expansion_Packs.zip
Again, launch the setup with Run As Admin, and make sure you temporarily suspend or exit any antivirus software prior to launching. I unzip the expansion packs zip file and copy/paste the contained files into the parent folder where the zip file lives, then also permanently set Run As Administrator prior to running those - also with antivirus software temporarily suspended/disabled.
Once install is complete, to complete the registration process, Dimension Pro must be launched with Run As Administrator or the registration will not properly complete. This is if you complete the registration process by launching Dim Pro in stand-alone fashion. If you want to complete the registration of Dim Pro from within Sonar, you can do so, BUT you must launch SONAR with Run As Administrator and then insert Dim Pro into the synth rack, where it will offer the registration completion dialog box. Either way is fine - I always set Run As Administrator for Dim Pro anyways, and launch it in stand-alone mode whenever I install it, but it is your choice as to which way you go.
http://www.cakewalk.com/support/kb/pages/x2_download_installation_instructions.aspx The above link contains further information on what is within each of the download files for X2, for each version.
I hope the above helps,
Bob Bone