Hi Sumitpatel,
'Inspiron 1464' laptop is not tested to work with 'Windows 8'; therefore its 'Windows 8' compatible drivers are not listed on Dell Support Website. However, you may try installing the 'graphic drivers' directly from the 'ATI website': http://bit.ly/QxvgT2
The suggested drivers are legacy drivers and may or may not work for you. You may want to give it a shot. Also refer to the list of all Dell systems tested to work with 'Windows 8': http://dell.to/SQojxk
Hope this helps. Do reply if you have any further questions; would be glad to assist.