How many times I can reset?

Depends on the pack purchased.
The pack basic has 1 use.
The pack standard has 5 uses.
And professional key, has unlimited uses (for a YEAR).

Can I reset the ink cartridges with this utility?

You can not reset ink cartridges with this utility. You have to do it from the CIS (continuous system) or use auto-reset chips. We do not provide these products.

I have a printer of the XP-XXX series with WiFi connection. The utility gives me communication error. What is wrong?

The printer must be connected only by USB cable! No Lan, no wifi! USB only!

Does the key have an expiration date?

No, it does not! you can use it whenever you want! only the professional key (unlimited uses) has restriction for one year.