Sir, In my lenovo y410 laptop i installed windows 7 after that i tried to burn win vista dvd.After giving options all the content on the dvd is safely copied then dvd rw opened after putting empty disc my dvd rw not dected still now.How to solve this problrm.

First of all, try to put other empty disc(or other disc, which contains data) in your dvd rw. See if it detects your CD. If it detects that means the problem is with your empty disc. If the computer an't detect your disc, go to Control Panel and see if any device has yellow mark. Make sure that drivers for your devices of your computer are installed correctly. If some device has yellow mark, that means you need to install drivers for this device.
If the problem continues, go to http://support.microsoft.com/mats/cd_dvd_drive_problems/en-us
for additional information.