The latter capability is extremely helpful when making large changes and has been added back into Mathcad with the 7.02a update. The arrow keys act a little differently than usual, but one gets used to this quickly. Version 7 uses floating math pallets for selecting mathematic symbols, operators, and Greek letters rather than menus. Surprisingly, this works well even on my laptop. The right-mouse button selections are well thought out, providing many frequently used menu tasks.
Installation works fine but be ready for some questions.
Like most programs these days, Mathcad uses a CD for installation. Problems occurred when I cancelled out of the installation program prematurely. I had currently installed. The installation program contains updates of both on the CD and asks whether you wish to replace your current versions with the CD versions. What it doesn't tell you is what versions you currently have or if the CD versions are newer.