The Windows License Agreement does not explicitly allow you to rent or lease hardware with the Windows operating system:
point 2 (…)
c. Limitations. The manufacturer of the device, the person or company installing the software and Microsoft reserve all rights (including rights under statutory on the protection of intellectual property) not expressly granted under this agreement. For example, this Agreement does not give Licensee any right to:
(i) separately use or virtualize the features of the software;
(ii) publish, copy (other than to make permitted backups), lease or rent the software; (…)
However, a separate document and the “Lease Agreement” remove this limitation for the Windows Pro version and other programs in certain license versions:
https://www.microsoft.com/pl-pl/Licensing/product-licensing/rental-rights.aspx
The relevant “Lease Agreement” document is available at the following address:
Therefore, it is legal to rent and lease equipment with Windows Pro operating system installed. The disclaimers in Section 2c(ii) remain in effect for the Windows Home edition and this software is still not allowed to be rented or leased.
Of course, the lease or rental must comply with the other provisions of the contract, in particular the software must be delivered together with the hardware on which it is installed (it is unacceptable to rent and lease the software alone).