It depends on what you mean by better.
The HP Desktop
has the larger hard drive meaning more space for data, programs, files etc.
The Toshiba Laptop
has the better CPU meaning faster processing speed.
The Dell Desktop
has more RAM meaning you can have more programs or apps open at once.
To use this 'Blender' software of yours, I would probably go with the Toshiba Laptop
As for the desktops...
Celeron processors aren't too good for newer software but it does have more memory than the other two. This shouldn't really matter though as no program ever uses over 1GB RAM. The HP has a Core 2 Duo which is a decent processor. It also has a larger hard drive capacity if you need it.
Dell desktop is out, no doubt about it. The HP you have is clearly the better desktop.
EDIT: arkhi, in the post below me has a fair point. Can you post the GPU's as well? You can see your full system specs by following the below tutorial. System Info - See Your System Specs