Windsor Company purchased a computer system for $77,300 on January 1, 2019. It was depreciated based on a 7-year life and an $17,100 salvage value. On January 1, 2021, Windsor revised these estimates to a total useful life of 4 years and a salvage value of $10,000. Windsor uses straight-line depreciation. Prepare Windsor's entry to record 2021 depreciation expense. (Credit account titles are automatically indented when amount is entered. Do not indent manually. If no entry is required, select "No Entry" for the account titles and enter O for the amounts.) Debit Credit Account Titles and Explanation Depreciation Expense Accumulated Depreciation-Equipment