Old Windows 7 HDD Works, but the Family Photos Are Missing
You do not need the original computer to read a compatible old SATA hard drive, but a working connection does not establish that the family photos were ever saved on that disk. Before running a deletion scan, check whether it is actually the right source.
In this r/datarecovery old-Windows-7-drive case, a family connected a 2007 WD 250GB disk and found only stock pictures, not childhood photographs. The poster ultimately suspected the missing photos might instead be on an old USB drive.
Check the Old User Locations and Other Media
If Windows can read the disk, browse existing Windows user profiles, Pictures, Desktop, Documents, and any application or camera-import folders. Check whether the original computer had a second disk, external USB backup, or removable camera card; a clean Windows installation alone does not identify where photos were stored.
Do not install software, boot the old OS, or write new files to the old disk while checking.
Scan Only If This Is Probably the Right Source
If there is good reason the pictures once resided on this disk and the drive is stable, preserve a copy and then inspect it for deleted photos. A readable copy may be evaluated with Recoverit Data Recovery or another file-recovery tool; export any verified results elsewhere.
If the disk never held those pictures, scanning it will not retrieve them. The user's later report is a reason to search old USB devices and other family archives before spending money on recovery software.