Getting files back on a Macbook Air and Encrypted Data

MacBook Air OS X (https://support.apple.com/en-gb/HT201260). I allowed a new folder to override one with the same name on my desktop. Can the data be retrieved and how much would this cost?

I have an encrypted windows laptop which recently wouldn't allow me to log onto the laptop and just comes up with a message to enter in a recovery key number. Once entering in the recovery key number it stated that it would allow me temporary access to the data but then would fail to do so and goes back to windows start up. I contacted my IT services who then did various tests on the drive, and tried to recover the drive to another working drive. It showed that the drive has various failures, including corruption which have affected the encryption and Windows installation. IT services have tried various recovery techniques, both for the encryption (repair-bde) and also for windows, but without success.

My client has stored years of customer details on his laptop (Apple Macbook Air) and cannot extract en mass. You would be required to extract to excel and CSV. Is this something you can help with? Emptied trash on mac and lost files, need files back

Many files and folders have disappeared, more disappear each time I connect the external HDD. Windows tried to "repair" the HDD. Could it be that the disk is encrypted? Almost all photos, about 80gb high Res photos. I managed to copy over 20gb that was visible but unsure if the rest is recoverable.

I have a Seagate external hard drive, which is not coming up on My Computer when I insert it and light is not coming on when it is inserted. There doesn't appear to be any external damage which has caused this so I am quite perplexed!

My advice is as follows - When files are deleted on a Mac it's very different to them being deleted on a Windows system. Windows doesn't delete the data it marks it as being available to overwrite, whereas Mac's will reorganise the disk and data will be gone very quickly. Regarding disk encryption, it's essential that you have the decryption code for the hard drive, as even if a data recovery company can fix the drive, the data will be useless without it as it will still be encrypted.