Do these windows files have verified Microsoft signatures?

[vfclists]

I am using Process Explorer to verify file signatures on Windows XP and the following Microsoft files are not verifying.

This in spite of running Kaspersky AV and currently AVG

svchost.exe

winlogon.exe

services.exe

regedit.exe

cmd.exe

ctfmon.exe

explorer.exe

lsass.exe

Does Microsoft supply verified signatures for these files?

If they do why aren't the AV programs flagging them?