You should enter "ALL" assets, and especially those that are already fully depreciated. If you don't enter them, then you risk an audit from the IRS asking you what your disposition of those missing assets was.
When you dispose of an asset you are required by federal law to recapture the depreciation on that asset and pay taxes on it in the year of disposition. So if you don't enter all of your assets, you risk getting a letter from the IRS asking you what happened to those depreciated assets, along with a bill for the depreciation on those assets.
If you claimed any SDA on an asset, (Special Depreciation Allowance) make sure you enter that in the program also.
