In (very) low earth orbit you can get by without radiation hardening. The ISS uses HP zbooks (and before that Thinkpads) and apparently they only really modify cooling and power, without any changes for radiation hardening.

Seems like they are reliable enough for their job and just need the occasional reboot. For more critical systems you could probably get by with three computers voting on the result, and if they disagree the outlier gets rebooted (a fairly standard setup in aviation and space)