@flogger12345
The VPCF1 series are notebooks and therefore it would be impractical to try the speaker on another PC. Also, as far as I am aware, there is no option to disable either left or right speaker.
Hi Ehtisham_Nisar,
Unfortunately this would seem to be a hardware problem but to be sure try testing the speakers. Open Control Panel > Sound > Playback tab and click on Speaker/HP. Then click Configure and run through the Speaker Setup to test output.
These are the instructions for Vista and your system may vary slightly...
You could also try some external speakers.
Rich