Based on Ryan's message at the top, if I downloaded Part 1 last night, do I need to download it again now? Also, are the Dim Pro and Dim Pro expansion pack downloads necessary if I have X1 -- or are they just duplicates? And, lastly, anyone know where I can get Windows 7 cheap? Thanks. Mark

You just need to download the remaining 3, if you did part 1. no need to download part 1 again, if its on your pc

I just upgraded from 32-bit Windows XP to 64-bit Windows 7.  I bought my Home Premium Upgrade from Amazon which is selling it now for a little over $100.  Just be aware that upgrading from XP straight to 7 will require a "clean install" as opposed to a simpler "update" from Vista.  It's no big deal really, but you should be aware of it.

Just came from a similar thread

If you downloaded part 1 , 2 3 and 4 should
Have downloaded automatically

The X2 DimPro + Expansion packs are the same as X1.

If you want to save money then go with Windows 8 and skip Windows 7.
On Oct 23 when it is officially released you will be able to purchase a download upgrade from XP to win8 for $39.99 US Dollars. Note: it will completely overwrite your hard drive so best to install on new drive. 
I went from XP 32 to Win 8 64 (Release Preview) and it is all working fine with Sonar X2 (so far).
 
To be safe, a bought a second hard drive and installed everything on it. I still have the XP32 hard drive to fall back on or copy files from if necessary.