"When X is" or "When X will be"?

I always have a tough time with this. Suppose the following:

The software will be installed when the computer is ready.

versus

The software will be installed when the computer will be ready.

Technically, both events are in the expected future (the computer being ready as a premise for the software being installed), but which one is right, or if they are both right, what nuance do they convey?

Solution 1:

The first one is correct. The second is wrong.

The reason is that you cannot use the Simple Future tense in Time Clauses, so those ones that start with when, while, before, after, by the time, as soon as, etc.

In your case, the Present tense is adopted; so, the correct sentence is:

The software will be installed when the computer is ready.

Solution 2:

The former.

It could even be rephrased to be a little more technically correct:

The software installation will begin when the computer is ready.

This correction goes for both instances of your phrase, since they both (kind of) indicate that the installation will be instantaneous - for example, depending on the computers readiness, that is when the software installation process can be decidedly successful / complete. If you're in a different situation then could you explain it in a little detail?

My reasoning for the latter being invalid is simply that it sounds plain wrong, inasmuch that 'when the computer is ready' is your condition for installation, 'when the computer will be ready' has a condition within a condition that can't necessarily be satisfied. There'll be technical terms, to be sure - but no doubt a linguist will notify me.