after running disk check on an external hard drive,Folder and files di

plz help,my important files were gone!
I have a 1T external hard drive( my passport Western Digital) .yesterday i right click on drive in windows 7 my computer --> properties --> tools --> check now --> and i check both these boxes :
-Check Disk dialog box Automatically fix file system errors
-Scan for and attempt recovery of bad sectors
after about 2 hour, process finished.but when i go to my external hard drive. i just found 30 gb of my files and folder was remain and other(about 900 gb!) were lost! and the free space of disk wasn't changed that maybe shows folder and files are not deleted.


why were the data deleted? Chkdsk tell nothing me when it completed! If data disappears it usually is because files are damaged and the Chkdsk utility attempts to separate the damaged files out BUT there aren't any files or folders with such as these names "found.000" or "*.chk" in my external hdd.( i remove check on hidden files)

note: i found my chkdsk log in event view in windows cp :
there ware a lot of records like this : Deleting orphan file record segment 60010.

i read some where that In the final chkdsk analysis, you need to have the disk directory and file structures reporting aligned with the sector 0 allocation table (or vice versa). is it really mean everything is gone?!

plz help to find prob and get my files back .