You will want to return to the Other Investment Expense section and go back to the questions and select either the "I'll spread the deduction over several years" option or - if you bought the computer new - the special depreciation allowance option for "I'll take the 50% special depreciation allowance and spread the remainder over several years". This last option should give you a similar tax result if you only chose partial 179 before.
Note: Due to some changes in from the Tax Reform Act, you may be able to claim 100% special depreciation instead of the 50% above if the property was purchased after September 27th, 2017
Section 179 is not eligible to be used for property used for the production of income, i.e investments (the program correctly recognizes this after you enter). But, I have forwarded a request to clarify that screen before you enter the information. The options for Section 179 should be removed or clarified before entry. It looks like that is just a generic asset entry screen as its used in different sections of the program, but for this section, parts of it don't apply.