My studio 1558 giving error meg 0146? but right now i can acess my hard drive is running fine

SOURCE: D610 DST Short Status Test Fail

It appears your hard disk has died and it may not be possible for you to retrieve your data.
Remove your hard drive from the laptop and insert it into an USB harddrive adapter, (they are not expensive and you can use it later as a external hard drive). Then plug it into the USB port of a working computer. The computer should/may see it as an external drive, if you are lucky you will be able to copy your data, if not, you are out of luck.
There are companies that can recover data from faulty hard drives, but it will cost you an arm and a leg for their service.

SOURCE: i get the error code 2000-0146 only when i run the f12 diagnostic

The 2000-0146 error code indicates a read/write failure of the hard drive. There is at least 1 sector that is failing on the drive. While it is working at the moment, the drive is failing and will over time degrade and eventually fail completely. Backup any important data, then replace the drive.

SOURCE: Error Code: 1000-0146; MSG: Unit 0:DST Log contains previous erro

Code 0146 is hard drive read/write failure.

Replace the hard disk drive

SOURCE: I have Inspiron N5010 .

This error indicates you hard disk drive is defective.

SOURCE: When I started my DELL Inspiron 1525 running Win 7

2000-0142 and 2000-0146 are hard drive SMART errors, indicating the HDD will fail.
To boot message about the AC adapter was a BIOS level message that normally appears when a Auto/air ac adapter or other 65 watt ac adapter is used to power the system.