Unfortunately i took out the HDD from Dell DNS323 file server and put it back. Which were in RAID0 format. Then i can't see my data folder there and don't get back anything. If anyone know how to retrieve these data please kindly advice me.
This is the one big reason why RAID is such a waste of time and space. There are two utilities I've used successfully to recover data in these circumstances - Recuva from http://www.piriform.com and Restoration 2514 from http://www.win-freeware.com/REST2514.htm. You don't need to install Rest2514 so there's nothing left ove when you've finished. Recuva takes up very little space and is worth keeping.
I have a DLink DNS323 which is the same product you mentioned. The drives inside the DNS323 are formated in ext2/ext3 which is the linux standard file system. If its a single drive you should be able to plug it into your computer after you install an ext2 driver to recognize it.
try http://www.fs-driver.org/ if your looking for a Windows ext2/3 filesystem driver. You can also try linux live boot cdroms that should allow you to migrate the data off the drive.
If you had 2 drives in the unit then it gets complicated. You would have to figure out the raid configuration and recreate it to retrieve your data.
Hope this helps
There is no problem in getting back all your data and files still. You should go for "Kernel for FAT and NTFS" hard disk data recovery software for the same purpose, in the demo of the software through scan mode you can check out the existence of your data on the drive. For more details just go through - http://www.harddiskdatarecovery.in