The extension is retroactive, meaning that someone who bought an Xbox 360 in the United States or Canada and paid for repairs within the last year is eligible for reimbursement. In many other countries, a one-year warranty already is standard.
"Customer satisfaction is a central focus and priority for the Xbox 360 system," Jeff Bell, a marketing vice president at Microsoft, said in a statement Friday.
Microsoft also said reimbursement checks for repairs done in the last 12 months will be sent out automatically in about 10 weeks. Contact information for warranty questions is available on the Xbox support site.
Microsoft has been the target of an online petition--with 3,382 signatures as of Friday--calling for a retroactive warranty extension to one year. The petition claims that Xbox 360 systems frequently failed after the original 90-day warranty and that customers were unreasonably required to pay between $50 and $129 for repairs.
Nintendo's Wii comes with a standard one-year warranty, with a free 90-day extension if customers register their consoles on the company's Web site. Sony's PlayStation 3 comes with a one-year warranty.