On Thursday, during a speech held in Tokyo, Microsoft Chairman Bill Gates noted that since Vista was released in late 2006, more than 140 million copies of the operating system were sold. If we compare Windows XP and Vista, things seem to be looking good; while XP reached 400 million users in 51 months, it only took Vista 16 months to go past the 140 million mark. As Bill Gates put it, “that’s a very rapid sales rate.”

Since the sales reflect Vista’s behavior on the market for a short period of time, the Redmond giant is apparently on track of meeting its goal of seeing Windows Vista installed on more than 200 million PCs in the first two years. We should assume that next to the legal licenses, millions of pirated copies of Vista are also being installed.

Although Vista sales are going up, lots of users that have been testing it complained about a wide range of issues. This is one of the reasons for which in March, Microsoft has released a service update for all versions of its operating system. The company claimed that this service update will improve not only the operating system’s stability and performance, but also its security.

Microsoft people have been quite busy, as at the beginning of April, Bill Gates hinted about the follow-up to Vista, Windows 7. According to News.com, Bill Gates said that the new operating system could be launched as early as next year. But for the time being, as News.com noted, it is still unclear if Gates referred to a beta or a final version.