The idea of this paper is to determine reliability and economic measures of a computer system by providing software component as spare in cold standby and priority to hardware repair over software upgradation. The hardware and software may fail independently from normal mode. There is a single server who is called immediately to conduct hardware repair and software up-gradation as and when required. The repair and up-gradation activities performed by the server are perfect. The random variables associated with time to failure, hardware repair and software up-gradation are statistically independent. The time to hardware and software failures follows negative exponential distribution, whereas the distributions of hardware repair and software upgradation times are taken as arbitrary with different probability density functions. The expressions for various reliability and economic measures are derived in steady state using semi-Markov process and regenerative point technique. The trends of some important measures of system effectiveness have been observed for arbitrary values of the parameters and costs. The profit of the present model has also been compared with that of the model Munday and Malik [2015].