Display issue in Ubuntu 22.04 DTS

[kalpana]

Over the past several days, I have had to reinstall several times for various reasons. However, there's one problem I cannot solve. This morning I turned off my computer. Then after an errand, I turned it on again and the display came up in 800x600 mode. When I look at display settings, there are no up/down arrows for me to select any other resolution. Is there another way to do this? I am using an old Viewsonic TD2420 which is capable of much better resolution, as seen after the installation. I can't afford to lose any more hair with this problem. Any ideas?

TIA,

Bill