Selling your old computer can help you pay for your new one, but you should be aware of the dangers. Others can access your personal information if it is not completely deleted from the hard drive. Using the recycling bin alone will not protect your information from someone with the skill to retrieve it. A better method is using software, which erases the data and rewrites the drive numerous times, preventing your data from being retrieved. According to Microsoft, "The bottom line is, if you're really concerned about identity theft, then don't give away your hard drive." Remove the information instead.
Delete files with Windows 7 Disk Cleanup. Run the program, and choose the drive you want to erase. Select the files to delete by clicking the text boxes, and click "OK." Or you can clean up all of your files by clicking on "Clean up system files" in the Disk Cleanup program, select your hard drive, and click "OK," then "Delete files."
Download Free File Shredder. Follow onscreen directions to install the software and add files and folders to shred. Set program options to shred files and delete your personal information. File Shredder will erase your data and rewrite the space with random data using your choice of five algorithms.
Download and install Eraser, following the onscreen instructions. Schedule files to erase or select the "On-Demand" option to erase data immediately. Eraser erases your files and rewrites the drive space with random characters to prevent anyone from recovering the data.
Download and install Complete Data Wipe. Complete Data Wipe will permanently erase hard drives, individual files, folders or partitions. It will remove your Internet activity and rewrite the space. Complete Data Wipe requires Microsoft.NET Framework 3.5 and works on Windows 7, Vista, XP, 2000 and ME.
Microsoft recommends removing all "e-mail contacts, messages, all documents, all files in the operating system recycle bin or trash folder, Internet files and any non-transferable software" before selling your computer. Removing the hard drive from the computer is the only way to be completely sure that your personal information cannot be retrieved.
Erasing and rewriting data can take a long time. Lock your computer to prevent use while your hard drive is rewritten.