Vista Won't Boot / SFC Has Error...

Hello,

I am having a problem with Vista Basic. It will not boot - it goes straight to startup repair. I have tried the startup repair and also ran CHKDSK /r, FIXBOOT, FIXMBR and SFC /SCANNOW (including the sfc /scanfile=d:\windows\system32\zipfldr.dll /offbootdir=c:\ /offwindir=c:\windows variation).

The error I get with SFC /scannow and the offline variation is "Windows resource protection could not start the repair service."

Can anyone please help? In the past, SFC /SCANNOW has worked straight away and fixed the boot problem.

Thanks in advance,

Al