I just upgraded to the new boinc software on two computers.

My desktop works fine but laptop won't connect to "localhost". I don't see any messages, tasks or anything.

I have tried uninstalling says "fatal installation". Tried downloading and reinstalling states setup not complete.

I can't even uninstall this software now.

Any ideas?

BOINC is in two parts:
An invisible part, called "the client", and
"The manager", a gui which allows you to see what the client is doing.
If these 2 parts can't talk to each other, (on port 31416), then naturally you won't be able to see anything.
Some firewalls will block this port unless specifically told to allow access.

As for the fatal install, it could be several things, one of them being permissions.

So, which OS, and which version of BOINC. (Some people using Linux also use the supplied BOINC, which is usually several versions behind the Berkeley version.)
If it's Windows, how are you trying to Uninstall?