My initial problem is:
A TPM error (7) occurred attempting to read a pcr value
Some of the suggestions on this involve disabling or enabling TPM. However, I have looked over the BIOS screens on my HP EliteDesk, and they do not seem to have such an option, or it is named something else.
I next tried reinstalling CentOS, but I am getting the error
"Can't read kernel : /images/pxeboot/vmlinuz".
The only suggestion I can find says to disable secure boot, but this is not enabled.