I have problem with my newly bought external hard disk. Yesterday, it was working fine.

But today, when I'm connecting my external hard disk, it took some time to show in My Computer and it getting automatically disconnect and connecting every 5-10 seconds.

Could someone tell me how to solve this problem?

Sounds like it might be a cable or connector issue.
I would verify the cables (power, USB) are secure, and try a different USB cable and a different USB port.

Best of luck,
WallyH

Actually this problem happens yesterday too, but it is rarely happening only 1 or 2 times in a hour. But today, it is getting worse, I get constant changing between connecting and disconnecting every 5-10 seconds on my external hard disk.

Btw, I use the same USB port as yesterday, so I wonder what's happening. The other USB ports doesn't even detect my external hard disk at all.

Edit: This problem doesn't happen in my laptop. But, it always happening in my PC.

Actually this problem happens yesterday too, but it is rarely happening only 1 or 2 times in a hour. But today, it is getting worse, I get constant changing between connecting and disconnecting every 5-10 seconds on my external hard disk.

Btw, I use the same USB port as yesterday, so I wonder what's happening. The other USB ports doesn't even detect my external hard disk at all.

Edit: This problem doesn't happen in my laptop. But, it always happening in my PC.
It is very strange that the other USB ports do not recognize the disk. To me, this sounds like a hardware problem in the PC or a USB driver issue. I'd make sure there are no driver updates for your PC. If so, install them.

WallyH