It started about a week ago, about half the time I turn my laptop on, it works fine and the other half it doesn't work and HDD makes a weird tagh tagh tagh tagh tagh tagh ... sound. It's like someone's knocking really hard.
Hey there. As clutchc correctly stated - unfortunately your drive is probably dying. You should backup anything important you have on the HDD. You can use DLG (Data Lifeguard Diagnostic software) and run both tests - Quick and Extended to see what happens.
Here's a link for DLG: http://support.wdc.com/product/download.asp?groupid=810
And here's a thread about unusual HDD noises/sounds which might be helpful: http://wdc.custhelp.com/app/answers/detail/a_id/568/
Hey there. As clutchc correctly stated - unfortunately your drive is probably dying. You should backup anything important you have on the HDD. You can use DLG (Data Lifeguard Diagnostic software) and run both tests - Quick and Extended to see what happens.
Here's a link for DLG: http://support.wdc.com/product/download.asp?groupid=810
And here's a thread about unusual HDD noises/sounds which might be helpful: http://wdc.custhelp.com/app/answers/detail/a_id/568/