If you use YMark2000 from National Software Testing Laboratories' Web site (www.nstl.com/downloads/y2000.exe) to test your Compaq PCs for year 2000 compatibility, you may have fewer problems than you think. The program behaves erratically or freezes during the Leap Year testing phase on non-MMX Pentium DeskPro 4000s and 6000s equipped with the G5 BIOS ROM (Revision 97.12.23 or later). The freeze-ups don't mean the systems will behave improperly in the new millennium, though. According to Compaq, increasing the BIOS's I/O delay time to 2600 nanoseconds solves the problem. To make the change, press <F10> during boot-up, select Computer Setup, then Built-in Devices, and finally System Information.