Reviewers will soon get their hands on the first release candidate of Windows Vista, which means Microsoft could be on target to deliver the OS to business customers according to schedule before the end of the year.According to sources familiar with the company\u2019s plans, Microsoft will be giving product reviewers access to Windows Vista Release Candidate 1 (RC1) as soon as Tuesday, with the code set to drop publicly as early as Sept. 5. Microsoft has maintained it would have Windows Vista RC1 available by the end of September.When Microsoft makes available the first release candidate of a product, it means the software is in its final stages of being ready to head to the manufacturer. The goal of making RC1 available is to show testers as close to a final version of the product as possible so Microsoft can identify and get rid of all of the last-minute bugs before putting the product on CDs."It\u2019s like throwing one of those roach bombs in an empty apartment and see what comes out," said Joe Wilcox, an analyst with Jupiter Research of the RC1 testing process. "They\u2019re looking ... [to see] if there any bugs hiding in the walls somewhere."Wilcox said it\u2019s likely Windows Vista will have at least two release candidates. If this is the case, the company could make its target deadline of releasing Vista to business customers in November, and consumers in January 2007.However, if Vista requires a third release candidate because of any problems or bugs that come up during the final testing period, "no way" will Microsoft hit its current deadlines, he said.With the last major upgrade to Windows, Windows XP, it was "not quite" two months between RC1 and the product\u2019s release to manufacturing, Wilcox said. If Microsoft indeed releases Windows Vista RC1 on Sept. 5 or thereabouts, the release to manufacturing\u2014and a release to business customers\u2014could happen as soon as early November. Microsoft has said it will release Vista to business customers in November, but has not specified at what time of the month.Original equipment manufacturers typically need about six weeks to get the OS installed and tested on PCs before putting those machines on the market, so if Windows Vista makes it to manufacturing by the end of November, it could hit its January release date for consumers. Again, Microsoft has not specified exactly when in January Vista will make its debut, though some speculate the company may want to make a big splash with Vista at the annual Consumer Electronics Show (CES) in Las Vegas. CES 2007 is scheduled for Jan. 8-11.Microsoft in March pushed back the release date of Windows Vista to November for business users and January 2007 for consumers. However, analysts suspect the release may slip further, and some Wall Street analysts have even changed revenue expectations based on this assumption.-Elizabeth Montalbano, IDG News Service (San Francisco Bureau)Related Links:\n\nMicrosoft Vista Pricing Leaks onto Website\n\nMicrosoft Releases Near-Complete IE 7 BrowserThis article is posted on our Microsoft Informer page.\u00a0For more news on the Redmond, Wash.-based powerhouse, keep checking in.Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.