Nearly half the owners of HDTV sets are unable to receive programs in high-definition because they do not subscribe to HDTV packages from their cable providers, according to a study by Forrester Research for the Best Buy consumer electronics stores. In a statement, Best Buy said Thursday that while the study indicated that one in three consumers are interested in installing a home entertainment system, they are confused about how it actually works. The retailers say their clerks ("Blue Shirts") have been instructed on how to prepare customers for the transition to HDTV.