2009NAV not installing. Getting "Another installer is currently running"

First I don't have the time to muck around with a 2009NAV install. My machine doesn't like it. 
I am running XP Home Edition with all the current updates.

 

I purchased a new subscription for 2005NAV, but never saw a download. 

 

I downloaded 2009NAV and can't get it to install. I see the message "Another installer is currently running..."

 

I tried removing the current copy of NAV (not sure which one it is) and get the same message.

 

All I want to do is get back to my original 2005NAV and download the new subscription.

 

Then I want a refund for the nonworking 2009NAV.

 

Thank you,

p14175