Hi @FuzzyRabbit, According to the document I found on the HP website, HP Printers - Windows 10 Compatible Printers, your PSC 1315xi is compatible with WIndows 10. Windows 10 Driver Restore. Colormunki Driver Windows 10 on this page.

HP PSC 1315 Driver HP PSC 1315 All-in-One Printer Driver for Microsoft Windows and Macintosh Operating Systems. HP PSC 1315 Driver Downloads Operating System(s): Windows XP, Windows 7 (32-bit), Windows 7 (64-bit), Windows 8 (32-bit), Windows 8 (64-bit), Windows 8.1 (32-bit), Windows 8. Lexmark X5250 Driver For Windows 10. 1 (64-bit) • HP PSC 1315 WinXP Printer Driver (36.89 MB) • HP PSC 1315 Win7 Printer Driver (362.68 MB) • HP PSC 1315 Win8 and Win8.1 Printer Driver (326.18 MB) Operating System(s): Mac OS X 10.6, Mac OS X • HP PSC 1315 Mac Printer Driver (18.56 MB) This driver works both the HP PSC 1315 Download.