We have 2 Dells at the office that were leased. The lease ends December 1st, so we just called this morning to see about shipping them back. They said, no, they will not take them unless we give them 90 days written notice first. It's in the fine print.
Why you have to give written notice for a lease that has an end date already is beyond me. We are shipping them back anyway, and not paying anymore. They got very rude and threatened to ruin our credit rating. Nice.
The Dell POSs crashed all the time anyway.

We are replacing them with Apples.