I moved some websites from an old Win2k Server to a new one with MDAC 2.8.
Suddenly, one of the sites didn't work anymore, with an error message like:
Microsoft VBScript run-time error (0x800A01F4)
Undefined variable: 'adUseClient'
or, in Italian as I got it:
Errore di run-time di Microsoft VBScript (0x800A01F4)
Variabile non definita: 'adUseClient'
Of course these sites are VB/ASP crap and I don't know VB/ASP. Nor will, I hope. So, after googling around for a COUPLE OF F*CKIN' HOURS I found that somewhat the author has forgotten a simple line:
<!-- #include file = "adovbs.inc"-->
Well, I don't know what this file is, nor where you can find it. I know it solved the problem. Maybe the next unlucky sysadmin will spend only a few minutes to get over this shit...