The biggest group affected by Microsoft’s July 17 layoff of 18,000 people are the 12,500 former Nokia employees who joined Microsoft as part of the Nokia handset acquisition. That leaves another 5,500 Microsoft employees, out of its current workforce of close to 130,000, who are being let go. Who are these individuals? Microsoft officials are declining to comment, unsurprisingly, beyond saying about 1,351 of all those cut will be based in the Seattle region. But sources close to the company said that the cuts are affecting just about every group at the company, everything from legal to Xbox. Microsoft’s unified Operating System Group, under Executive Vice President Terry Myerson, is one of the units that will be affected immediately and directly, sources say.