We recently received new computers and went from Windows XP 64bit to Windows 7 64bit.
We're still using SW2010 and it was originally installed as SP 3.0 by IT. We downloaded the 3.0-5.0 service pack and once that was installed the installation manager pops up everytime we start solidworks. I ran into this a few years ago and can't remember how I fixed it.
We have local admin rights fyi.