I had ibm thinkpad r40e n I had formated and downloaded drivers from lenovo's site but they aren't working.so please give any link for downloading drivers or service centre details?

You will find them al on Lenovo's site.
All here: Drivers and software - ThinkPad R40e (http://support.lenovo.com/en_US/research/hints-or-tips/detail.page?DocID=HT072046)

Just select what you need..