Does this show up on all screens? Reboot the system and at the Dell Splash Screen tap the F12 key.  Select the option to run the Dell Diagnostics. Run the video tests and see if the line shows up. If it does contact Dell support and have the system replaced.

Yes its shows on all screens....and can u pls lead me step by step how to get to reboot it the system... tnx

just turn it off and then turn it back on. once you see the Dell splash screen start tapping the F12 a few times

All test pasted...:s its not that.... can be that from scratch or some defect on the screen? tnx

did you see the line during the test? That is the point of running the video tests. If the line shows up during the test then the screen is defective and it needs to be replaced.

yes i see the line during the test :S  tnx a lot peace...