I have an interesting problem, my portable hdd cannot be seen when plugged on usb. But i can see it on driver manager. And i also cannot open Disk administration. A 3-5 min. later A hdd comes up in My Computer with name Local Disk J. It doesn't says its capacity. But When i plugg it off, There is a Philips HDD coming up for 0.5sec on My Computer and it opens autorun. Please help me.

i suspect bad sectors on ur drive. The drive initializes , goes for mft to give u ur folder and file structure , but some sectors there are responding slow. So ur hdd hangs a bit here and there. U need to clone ur drive on to a good one. Another possibility is the read/write heads are going , in this even cloning urself can wear em out fully. U can try runing surface scan ( mhdd for example ) on ur drive ( need to connect it to mother board directly ) and if in the begining ull get some slow/bad sectors - thats ur culprit.

Thx for your fast reply. I'm new to this hdd thing. I downloaded and writed ISO image to a cd, and i plugged hdd to motherboard so what i'm gonna do ?

Ok so u have a bootable CD with MHDD on it and ur bad hard drive connected to the mother board. Now u need to start the computer. Disconnect the all the herd drives with the exeption of the one u planing to test and the DVD rom with MHDD image in it. BIOS should recognise the DVD and ur HDD pluged in and then u need to boot from CD. Some BIOSes have F12 button upon startup as the trigger to do manual boot ( gives u options what to boot from , then u can choose DVD rom or CD rom maualy ) some Bioses have no feture like that in that event u need to get into BIOS and make sure that DVD stays above then HDD in boot priority.