Data recovery FAQ: answers to your questions
Find answers from our specialists to the most frequently asked questions about data recovery: hard drive failures, SSD, RAID, USB drives, pricing, turnaround times and process. SOS Data Recovery (Tesweb SA), Swiss specialist since 2006 with over 10,000 cases handled, answers your questions.
Why consult our data recovery FAQ?
Our technicians answer the most frequently asked questions about hard drive, SSD, RAID, NAS, USB drive and memory card failures. Each answer is based on over 10,000 cases handled since 2006 and regularly updated. If you cannot find the answer to your question, contact us — free diagnosis within 3 hours.
Is it possible to recover deleted data from a partially overwritten hard drive?
Partially, yes. Overwriting a hard drive does not instantly destroy all data. Several mechanisms allow for partial recovery:
- Partially overwritten files — if only the header or end of a file has been overwritten, the rest can often be reconstructed
- File carving — a forensic technique that searches for file signatures (magic bytes) directly in the raw sectors, regardless of the file system. Effective even after reformatting.
- Spare sectors and HPA zones — some drives keep copies in areas inaccessible during normal use
- Magnetic remanence — on older HDDs, traces of previous writes can sometimes be detected with specialized equipment
A secure overwrite with multiple passes (DoD 5220.22-M or Gutmann standard) makes recovery practically impossible. A simple quick format or a standard deletion is not enough.