After I buy the computer, can I rely on the company for assistance? * Hundreds of companies sell personal computers (PCs), but look beyond the flashy price, and the shortcuts begin to show. How well-built is that clone anyway? And how much technical support will the company provide after the sale? Only a handful of PC makers get consistently high ratings for reliability and service. When computer magazines PC Magazine and PC World made independent assessments earlier this year, they agreed that three companies deserved top honors: * Compaq, Digital, Hewlett-Packard. The costs of these machines are higher than the average, but maybe that's because they build in quality and back it up with great technical support. * The two magazines also rated two other companies highly - Apple and Dell. Micron, a perennial favorite in the past, is merging with financially troubled Zeos, whose quality has suffered in recent years. IBM received top marks from PC Magazine but not PC World. Packard-Bell, which dominates the retail computer market, received poor ratings.