Cost of replacement parts will be quoted by Comserv and the customer is at liberty to purchase the parts from Comserv or from other sources. One additional point is deducted for parts installation when parts are purchased from other sources. For example, our obligation during a hard disk drive (HDD) replacement is to install and test MS DOS, MS Win 3.11, MS Win95, MS Win98, MS Win ME or Win XP only. Any other software installation, configuration and test shall be chargeable at 0.5 points per man-hour.