I've LG TV 42LB5820-TB. I connected external USB HDD 1 TB. TV initialized the external hard drive & now I am able to record TV programs on it & play it on the same TV as well. But when I connected the hard drive to my laptop it showed drive letter but the hard drive was inaccessible. May be LG TV formatted it in a file system that my windows laptop can't recognize.

Please tell me how I can transfer recorded program to my laptop running windows 7. if anybody knows the solution I'll be very thankful to you.

Your manual should tell you what file systems the TV is capable of identifying for the usb connection (fat fat32 ntfs etc.). You can try formatting the drive (lose your recordings) then initialize it with the PC not the TV and if when connected back to the TV it initializes it again try to record a few minutes and then try the PC again. If no go, contact LG for info. I see it records in Divx, do you have Divx HD codec on your PC? You can also copy a few video files to a flash drive (avi mp4 mkv wmv divx etc.) from the PC and then see which ones the TV can recognize when plugged into the TV. Did the TV come with a disc for installing software on other devices that can connect? There is a picture on the manufacturers site that shows a PC, Tablet, and smart phone connected to the TV. What happens if you connect the PC to the TV can you see the drive from there?