Bobbi,
I have had similar issues with guard.tmp and entries in my hosts file. After repeated running of Adaware and Hijackthis, the hosts file and guard.tmp have stopped appearing, however I have found this - everytime I reboot, I see a number of new .dll files in my system32 folder. (enjql1151.dll, e0202afmgd2a2.dll, arsnds.dll, etc all around 219KB in size).
I found this registry key - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\MediaContentIndex -> DllName C:\WINNT\system32\enjql1151.dll
Any ideas whats happening here?