First there is a GD round wherein you are given 3 min to talk about any one of given topics individually. Here they just check your communication skills and your confidence level.
Then comes the technical Aptitude round which consists of basic questions regarding windows OS, its shortcut keys, fundamentals, versions comparison, troubleshooting. It has multiple choice.
Next round is the telephonic round wherein an employee has a conversation with you over the telephone he/she may ask you about your day, about family, about convergys, a moment from past which you remember, about your friend. Here much of the focus is on your communication skills over telephone, empathy, listening skills, clarity in thoughts.
Next round is again technical aptitude cum typing test round
Finally there is Operations round where in you are asked about various versions of the Windows OS, difference among them, OS fundamentals, Windows Shortcuts and Normal troubleshooting steps for windows.