i have got a hdd which restarts continuosly, it doesnt even start in safe mode. then i connect it to another system making it secondary slave now the problem shifted to mine as well...... both hdd are showing the same problem what could be the possible problem??? and pls let me know the solution as well...

You must have the jumpers on the back of the hdd set to the proper setting

i checked with jumpers they are fine.... any other possible prob???

On the first HDD that was starting over and over the issue could have been software such as virus/malware/or driver problem or it could have been hardware issue.

When you moved it and slaved it to other computer and it keeps causing a system to restart then it is most definately a hardware problem...either the jumpers are incorectly set or the drive is bad.Since you say the jumpers are properly set...then it must be the drive is bad.

Note..........no virus or malware or spyware can jump from partition to partition or drive to drive. It can be transfered by copying files and applications. So unless you left some valuable information out then you have more than likely a bad hdd!