Late July — Microsoft's most recent delivery target for Windows XP Service Pack 2 (SP2) — is right around the corner. But that isn't stopping Microsoft from continuing to tweak the code.

Typically, Microsoft makes few or no feature changes to a product once it enters the near-final Release Candidate (RC) stage.

XP SP2 hit the RC1 beta milestone on March 17. Company officials have said publicly to expect the product to reach RC2 status some time in May. Microsoft officials have targeted "late July" as the release-to-manufacturing date for XP SP2, with a revitalized "Protect Your PC" marketing campaign, designed to focus on SP2, to launch in September.

"The final release is still expected this summer," a Microsoft spokesman confirmed on Friday. " As for whether there will be an RC3 — that is dependent on the customer feedback generated during the testing process."

Microsoft's Windows XP SP2 is largely, although not exclusively, a security-oriented update to the now-three-year-old Windows XP client. With SP2, Microsoft is turning on its built-in Windows Firewall by default; including new browser and e-mail safeguards; enhancing XP's memory protection features, company officials have said.

XP SP2 testers, who spoke on the condition of anonymity, said the Redmond software vendor has made changes to the XP SP2 code since the introduction of RC1. While none of them seems as if they would require any kind of major tinkering with the core of XP SP2, they are still changes.

Among the tweaks that Microsoft is said to be planning to include in RC2: