Is there any way to completely remove cakewalk and reinstall without it remembering your old setting..I just upgraded and its messing with my plugins...

Please don't remove Cakewalk, we need them to make software!

But seriously, I sense regedit...

1. Use the uninstall utility.
2. Start -> Run... -> "regedit"
3. HKEY_LOCAL_MACHINE\SOFTWARE\Cakewalk Music Software\SONAR Producer\7.0 (Delete the "7.0" key and it's contents)
4. HKEY_CURRENT_USER\Software\Cakewalk Music Software\SONAR Producer\7.0 (once again, delete the "7.0" key)

Should be enough to clean Sonar out.

Deleting the Sonar 7 folder is also a good idea

Wipe the hard drive is the only method guaranteed by Blackwater.....

First, remove using Add/Remove programs, delete applicable Sonar folders in All Programs (assuming using XP) as previously stated, use Regedit to remove the previously stated keys, and that should do it.

ORIGINAL: sanctioned

Is there any way to completely remove cakewalk and reinstall without it remembering your old setting..I just upgraded and its messing with my plugins...

Are you talking about installing a different version than the one that you already have? If so you should NOT remove the older version.

I bought and installed Sonar Home Studio 7 on my laptop but discovered that my sound card is not correct. I want to uninstall the program from my laptop and reinstall it on my PC which does have a good sound card. How do I do this without having to repurchase the program.  Where is the setup file?  

The set up files are on the disk you purchased.  It WILL show up in your online Cakewalk account but it is NO longer available for download through the site.
 Your only option is to use the Disks or Purchase the new sonar home studio (which blows HS 7 out of the water in my opinion) for like 50 USA Dollars. 

https://www.cakewalk.com/Support/Knowledge-Base/2007013372/Clean-Install-All-Cakewalk-Software