Steps to reproduce:

1. Directly run the uninstaller for QNX SDP 6.5.0 SP1 (not through control panel).
2. Before restarting also run the uninstaller for QNX SDP 6.5.0 (again, not through control panel).
3. Restart.
4. Run the installer for QNX SDP 6.5.0 and you will see the following message:

"The installation cannot continue because this product is already installed.  If you wish to reinstall it, please 
unistall it first."

5. Referring to other related issues on this topic I found a cleanup utility at

http://www.qnx.com/download/group.html?programid=20905

6. Run the clean up utility for SP1 and the regular installation.
7. Restart
8. 4. Run the installer for QNX SDP 6.5.0 and you will see the following message:

"The installation cannot continue because this product is already installed.  If you wish to reinstall it, please 
unistall it first."

So you see, even after I run the cleanup utility, I still cannot reinstall the QNX SDP.  I am running Windows 7 
Professional SP1 on a Dell Precision M4700.