Vista Boot Problems - ComboFix Will No Run

Running Vista Home Premium 32-bit, SP1.

Vista will not boot normally. I get to the black screen just before the Welcome, and then... nothing. Just a black screen.

I CAN start in safe mode with networking, however. I disabled EVERYTHING in the msconfig startup, as well as all non-Microsoft service, to no avail.

When I try to run ComboFix, I get the msg 'ComboFix is preparing to run', followed by 'Acess Denied. Administrator permissions are need to use the selected options. Use an administrator command prompt to complete these tasks'.

I did right click on the CF icon on my desktop, and selected 'run as administrator' but got the same result.

If I just let it run as is, I get the usual 'Scanning for infected files... This typically doesn't take more than 10 minutes, etc...', but nothing ever happens. It just stays there, on that blue screen... forever.

I do have a MS Vista install disk, and I've run Startup repair. No change.

 

ComboFix DID finally start up, although it took maybe 15 minutes for it to start. However, while its running through the 50 stages, embedded in those stages is the occasional ''Access Denied. Administrator permissions are needed....".

The completion of CF and subsequent restart did absolutely nothing to change the boot problem.

 

Wow, I guess you guys ARE a small forum.... I was hoping to get some response by now (other than my own).

Anyway, I have continued to play with safe mode & vista boot disk, running sfc /scannow, running chkdsk /r, running startup repair from the Vista boot disk, and running a series of bootrec commands at the command prompt accessed from the Vista boot disk, and still nothing....

Maybe this is NOT the proper forum, since perhaps it is not some kind of malware problem.

I've gone into Event viewer after an unsuccessful attempt at normal booting, and I see the msg:
The COM+ Event System detected a bad return code during its internal processing. HRESULT was 8007043c from line 45 of d:\vistasp1_gdr\com\complus\src\events\tier1\eventsystemobj.cpp.

Can anyone at least direct me to the proper forum if this is not it?