Dell recovery
linky Dell Backup and Recovery is available on Dell Precision, Latitude, Optiplex and Vostro computers that run Windows 8, Windows 7 and Windows Vista operating systems
These procedures can only be done if the recovery partition on your hard drive is still intact
These instructions are for the Windows 7 operating system
How do I find out if the recovery partition is still intact?
Open Dell Backup and Recovery by clicking Start, pointing to All programs and clicking Dell Backup and Recovery
Click Restore System
If it's there, it'll work, if not, see above replies. I'd do a fresh install of Win10 if recovery isn't available. Win7 is no longer supported. If however you want to keep Win7, it's cheap enough, worth a shot.
Win7 linky
