My laptop can detect my hard drive but i cant access the files in it

You can recover files from hard drive with asoftech data recovery program. download the program from
http://www.asoftech.com/adr/
It tells the steps how to perform data recovery.

If above does not work, you may have to format the hard drive (use quick format), and then use above mentioned software to scan again the hard drive and recover your files.

If it shows up in 'my computer' as a drive letter(like E: drive) but you can't access your files on it,you can recover data from hard drive with data recovery program.
Tenorshare data recovery is a good hard drive data recovery software. It can recover data after deeply scanning your hard drive to look for lost data due to drives crash, physical damage,system sabotage, virus attack etc.You can get it here: http://www.any-data-recovery.com/product/datarecoveryprofessional.htm
After you recover your data,you can format it to check out whether it can be fixed.

Have you tried this hard disk on another computer? How does it show there? Is it read well there? Or is it asking you to format before any access? In fact, I do know there is some hard disk data recovery software that can help recover lost or deleted data from hard disk with ease steps. If you are interested, also give such software a good try.
But, if this drive even cannot be recognized on any computer, your drive must be damaged seriously somehow. If the inner files are really very, very important, you'd better ask some data recovery agencies for help.
Hope these words can help you somehow.

Why you cannot access the files inside this hard drive? You've got a not formatted error or RAW file system error? Or you've formatted this hard drive somehow?
If so, to re-access your desired drive stuffs, do not write anything new on this drive and try to take your desired drive files back with hard drive data recovery software.
Know any data recovery program that can works well in your situation?
If not, here are some clues for you to go on:
Use data recovery software to rescue lost or deleted drive files back
Prepare drive data backups well on different drives to avoid such data loss troubles in the future.

What do you mean by "can't access the files in it"? Get any error message?
Have you tried to assign a letter for it in "Disk Management"?
Just right click it in Disk Management and select "Change Drive Letter and Paths..."
If this way makes no difference, you may have to restore these files back by using data recovery software.
When it comes to data recovery software, people would recommend you to use some data recovery freeware that works well and is free for every user.
Check these data recovery freeware here:
http://www.geeksdo.com/freeware/data-recovery.html

Your files are still in your hard drive. Only the space is made available to other new files, but the old data is still there. In another word, deleted file can be recovered as long as the space is not overwritten by new files.You can recover deleted files from hard drive and Card Data Recovery must be the best choice.http://www.card-data-recovery.com/recover-deleted-files.htm

If the drive is detected you can recover data using a data recovery software. I will suggest you to use "Kernel for FAT and NTFS" a effective and easy to use software to recover recover data from inaccessible or even corrupted external drive. The easy to use interface allow even novice user to recover data. http://www.windowsdatarecovery.net