Which parameter of the alternative marketing mix 4cs does a company use when it offers to install a computer that you purchased from that company

Convenience.

The traditional marketing mix is known as the 4P's (product, price, place, promotion). The alternative marketing mix is the 4C's (consumer, cost, communication, convenience)

Installing a computer that you bought from that company is an example of convenience because it allows the consumer to make one easy choice for all of their needs.