If you are planning to buy a branded PC you may want to buy it this week itself because Microsoft plans to phase out they very popular Windows XP by the end of this year saying Windows Vista is ready to take over.

Microsoft’s Vista version launched 18 months ago could not catch up with XP on the popularity charts and this even led the company to postpone the end of XP’s sales from January to this month.

So now for people looking to buy a computer from a branded store like HP or Compaq, will not come with XP loaded.

“The users are asking Windows XP because it is user friendly. This provides us an advantage of selling assembled PCs over branded ones,” said Sameer Mehta, a computer seller.

One of windows biggest strengths of Windows XP is the familiarity that it brings with it. Since it took a while for the users to get used to XP and the same could be argued for Vista version.

But given the higher hardware requirements of the Vista, the transition may not be as seamless as Microsoft would like it to be – especially in a price sensitive market like India.

“We are investing a lot so that we keep tweaking Windows Vista and keep listening to consumers and partners,” said Tarun Gulati, COO Microsoft India.

Users may soon not have much of an option when it comes to choosing their operating system.

Even as competitor Google is working on an operating system of its own for more in the industry, ironically the biggest threat to Vista may not be from Apple or Linux but Microsoft's very own windows XP at least for now.