Hi tirofijo,
Thank you for taking the time to post your issue.
I’m going to need you to answer a few questions for me.
1.
When did this first start?
2.
Have you ever been able to use the wireless?
3.
What is the make and model of the router and wireless card you are using?
Can you please bypass the router and hook the Ethernet cable directly from the modem to your computer and check to see if you can access the internet?
The following Microsoft Article goes over a certain situation where Windows Vista cannot obtain an IP address from certain routers. It does include steps to attempt to address the issue
but I would like to know the outcome of bypassing the router before proceeding with the steps outlined in the article.
Windows Vista cannot obtain an IP address from certain routers or from certain non-Microsoft DHCP servers
http://support.microsoft.com/kb/928233
Thanks,
Keith
Microsoft Answers Support Engineer
Visit our Microsoft Answers Feedback Forum and let us know what you think.