(In reply to Dave Flanagan from comment #11) > My configuration is certainly a possibility. My hardware is a getting old but I don't think ancient :-) ...all drivers are current although Windows 11 isn't supported. > > I don't see redraw type bad behavior anywhere else and in Thunderbird mouse moving or changing focus doesn't fix the problem. > > OS Name Microsoft Windows 10 Pro > Version 10.0.19044 Build 19044 > System Manufacturer Dell Inc. > System Model Latitude E7240 > System Type x64-based PC > Processor Intel(R) Core(TM) i7-4600U CPU @ 2.10GHz, 2701 Mhz, 2 Core(s), 4 Logical Processor(s) > BIOS Version/Date Dell Inc. A29, 6/13/2019 > Installed Physical Memory (RAM) 8.00 GB > --- > Adapter Description Intel(R) HD Graphics Family > Adapter RAM 1.00 GB (1,073,741,824 bytes) > Installed Drivers igdumdim64.dll,igd10iumd64.dll,igd10iumd64.dll,igd12umd64.dll > Driver Version 20.19.15.5063 i7-4600U is pretty long in the tooth as it's from 2013. The latest official drivers for your GPU (HD4400) direct from Intel are dated 2-5-2021 / 15.40.48.5171. The 20.19.15.5063 drivers from comment 11 appear to be from Dell's own site and are dated from 2019. It's up to you but you could always give them a shot to eliminate the possibility of it being a drive bug. They're here: https://tinyurl.com/15-40-48-5171
Bug 1760447 Comment 12 Edit History
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(In reply to Dave Flanagan from comment #11) > My configuration is certainly a possibility. My hardware is a getting old but I don't think ancient :-) ...all drivers are current although Windows 11 isn't supported. > > I don't see redraw type bad behavior anywhere else and in Thunderbird mouse moving or changing focus doesn't fix the problem. > > OS Name Microsoft Windows 10 Pro > Version 10.0.19044 Build 19044 > System Manufacturer Dell Inc. > System Model Latitude E7240 > System Type x64-based PC > Processor Intel(R) Core(TM) i7-4600U CPU @ 2.10GHz, 2701 Mhz, 2 Core(s), 4 Logical Processor(s) > BIOS Version/Date Dell Inc. A29, 6/13/2019 > Installed Physical Memory (RAM) 8.00 GB > --- > Adapter Description Intel(R) HD Graphics Family > Adapter RAM 1.00 GB (1,073,741,824 bytes) > Installed Drivers igdumdim64.dll,igd10iumd64.dll,igd10iumd64.dll,igd12umd64.dll > Driver Version 20.19.15.5063 i7-4600U is pretty long in the tooth as it's from 2013. The latest official drivers for your GPU (HD4400) direct from Intel are dated 2-5-2021 / 15.40.48.5171. The 20.19.15.5063 drivers from comment 11 appear to be from Dell's own site and are dated from 2019. It's up to you but you could always give them a shot to eliminate the possibility of it being a driver bug. They're here: https://tinyurl.com/15-40-48-5171