Updating to 5.5 will I still have 5.1

This may have been discussed before but I could not find a clear answer.
If I upgrade to 5.5 will I still have the option to run 5.1?

Yes.

Fredo

To further clarify this, 5.1’s icon will remain on the desktop, as 5.5 installs to a new folder altogether.
It will import prefs from earlier version though, so if you do not want it to do this you’ll need to take the usual steps to prevent it.