Exit, Stage left!Problem solved guys, thanks for your help. My WinXP wireless network config was DHCP, no specified gateway or DNS and it works fine.After reading Evol's post, I re-checked my config on Vista and found that I had indeed specified the router IP as the default gateway. Just for the heck of it, I specified the router's IP in the Primary DNS and that did it! Though it works fine, I'm confused:1. Why do I need to specify the DNS server when the BSNL DNS servers are configured on the router AND I have specified the router as the default gateway?2. Why DHCP is working erratically on Vista. There's a real problem here because the allocation range specified on the router starts at 192.168.1.33 whereas Vista (when it works, it takes a long time) gives itself an IP in the 168 series!To push Vista, I tried WPA2-PSK with a static IP and it works just fine.Essebe, where can I contact the author of the PDF link you gave me? There's an error in the MTU value specified in the screenshot. The default is 1500 but 1492 should be the value if you want most sites to work. I could be mistaken but I remember that nugget when I got the router a year ago and couldn't open Yahoo, Gmail and several other sites. Thanks again guys.