Hello,
TruScan/Proactive Threat Protection can be installed and run on all 32-bit non-server operating systems such as Windows 2000/XP/Vista/7 (x86) and 64-bit Windows XP/Vista/7
However, In your case, I would recommend you to Simply uninstall ONLY the PROACTIVE THREAT PROTECTION feature only from the Add/ Remove Programs and REINSTALL it again.
Also, check if the Proactive Threat Protection Policy is enabled from the SEPM?