Good day, I cannot access my TrekStor external hard drive. Is there a way I can get it to work without formatting it and losing the data? I am running Windows 7. Kind Regards, Dries

There are two options for you to get your drive stuffs back right now:
1). Do not format this RAW file system external hard drive temporarily and plunge it to your PC. And then, choose and apply RAW external hard drive data recovery software to scan this drive and find your preferred drive files back as many as possible.
2). Directly consult some professional data recovery services from some data recovery companies or agencies.
In the future, remember to save copies of everything important on at least two devices in case of any similar data loss issues.

try other usb port, or other computer and see whether the hdd is detected. If still not, try to go to device manager ( http://www.computerhope.com/issues/ch000833.htm ), and then assign a drive letter to the hdd. After that, try to access it from Computer, if not able to access it, format it (use quick format) and then use this file recovery program called asoftech data recovery to recover your files.
External Hard Drive Recovery Software

try other usb port, or other computer and see whether the hdd is detected. If still not, try to go to device manager ( http://www.computerhope.com/issues/ch000833.htm ), and then assign a drive letter to the hdd. After that, try to access it from Computer, if not able to access it, format it (use quick format) and then use this data recovery program called asoftech data recovery to recover your files.
http://www.facebook.com/pages/Asoftech-Data-Recovery/290956907592436?sk=info

try other usb port, or other computer and see whether the hdd is detected. If still not, try to go to device manager ( http://www.computerhope.com/issues/ch000833.htm ), and then assign a drive letter to the hdd. After that, try to access it from Computer, if not able to access it, format it (use quick format) and then use this file recovery software called asoftech data recovery to recover your files.
http://www.asoftech.com/adr/

Mechanical damage. Last possibility to retrieve the data on it: open the case, extract the hard disk, put it in a desktop and try to access it in there. If even this fails then it's dead, junk it.

To access the files off the hard drive another way - remove the hard drive from the case and connect it to an USB hard drive adapter and then plug it into a working computer's USB port. If the computer see the hard drive as an external hard drive/storage device and you can open the folders and files then backup your data. This also indicated the hard drive is OK and the Western Digital case/electronics is faulty.
To use this as an external USB hard drive, put the hard drive in an USB adapter case.

Please click the links below;

http://ezinearticles.com/?RAW-File-System-Partition-Recovery&id=2606031

http://blogs.technet.com/ganand/archive/2008/02/22/what-is-this-raw-file-system.aspx

http://www.z-a-recovery.com/art-raw-filesystem.htm

Hope this help.
All the best!

Use EASEUS Data Recovery Wizard to recover the data. You can find the program on the internet..

To format afterwards click Start, click Run and type compmgmt.msc.. In there format your drive..

If the drive was formatted in a newer windows OS and it is the NTFS file system, the Mac OS will only have read access. You can check this by plugging it in and checking the properties. To solve this you can copy your stuff off and reformat in the FAT32 format, you will only lose the security features that NTFS offers.