Below steps derived from “The Geek Page”, dated January 28, 2022 By Saurav Dey.
This permanently fixed my problems with Epson Scan on Windows 11. No reboots, needed, no turning on the scanner before startup needed. YMMV.
Step#1: In the search box, type Run and select it from the search results.
Step#2: In the Run dialog box, type services.msc and click OK.
Step#3: The Services window will open. Scroll down and locate Windows Image Acquisition or WIA.
Step#4: Make a right-click on the WIA and select Properties from the drop menu.
Step#5: In the WIA panel, click on the Log On tab.
Step#6: Under the Log On tab, select the Local System Account option. Check the box beside Allow Service to Interact with Desktop and clickApply to proceed.
Step#7, restart the Service then restart the computer. Epson Scan should now work.
Additional note: When Epson Scan starts if the “Preview” & “Scan” buttons are not visible then click once anywhere in the left hand panel & then press the keyboard “Alt” key. The buttons should now appear. (this part is from Epson support).