The antivirus software supplier made the announcement as it said it would delay filing its results, which are due on 31 March.
The company is under investigation by the US Securities and Exchange Commission (SEC) and the Department of Justice.
The restatement will reflect revenue on sales made by distributors to customers. In the past Network Associated used to book products shipped to distributors as sales.
The company said the changes should not affect financial results reported in or since financial year 2001.
A year ago, Network Associates announced that the SEC was looking into questions about the company's accounting, but this is the first time it has said the Justice Department is also involved in the probe.
It is unclear when the Justice Department joined the investigation.