I just downloaded WindowBlinds 7 from Impulse and went through this same thing (previous versions were MUCH easier as Impulse wasn't involved!). First, Impulse has no readily visible info on how to download & save software when you don't want to install it on the spot. By fooling around and right-clicking on things, I discovered the "Download and Archive" option. Selected that. Watched it download all 54.20 MB of WB7. Impulse does not show the download filename was or where it was saved to. Finally, out of frustration, I did "Download and Archive" again, and at the end of the download, I got a pop-up box that revealed the secret archive location, because it said "you already have this here, do you want to overwrite it...". I grabbed a pen, wrote it down, and typed the info into a text file that is now part of the zip archive containing the backup copy of WB7 and my registration/receipt docs. This is where Impulse put it:
C:\ProgramData\Stardock\Impulse\backup\WindowBlinds 77.20.036_03.24.2011.impulse
Let's hope that future revisions of the Impulse software makes these things readily visible. A standard "Save As" dialog box would be great...