If the problem persists after the initial theory (replacing the CMOS battery) is tested and does not resolve the issue, a new theory must be established. In this case, the next logical step would be to check the motherboard for issues, as a faulty motherboard can also lead to inaccurate system date/time records and is a testable, next step. Escalating the issue may be premature if further onsite troubleshooting can address the problem. Updating BIOS or replacing the computer altogether without further diagnosis does not apply the best troubleshooting practices to correct the issue.