Yep, that's me.
*plays KQ2*

I KNEW it.

Admins, please close this thread then...

Another one to add to the list of culprits, though:
Portpro.sys

Google's not having any luck, is it related to the PortPro port scanner?

Cranky, do you know how you got it? Any game adapters, such, install it? Do you still have the file and can rip out any identifying info? (Right-clicking on a sys file, you can sometimes pull up properties, and from there version info and stuff)

Here's the text of the file.

MZ ÿÿ ¸ @ À º ´ Í!¸LÍ!This program cannot be run in DOS mode. $ ýï’û¹Žü¨¹Žü¨¹Žü¨¹Žý¨´Žü¨Ã_Â_墨Žü¨Q‘ö¨¸Žü¨Rich¹Žü¨ PE L [O´< Ã_

@ È € Ã_ € ˆ Ã_ ( € < ` T 8 .text › € Â_ € h.rdata ” Â_ @ H.data À À @ ÈINIT Å’ Ã_ Â_ Ã_ â.reloc V € ` € @ B\ D e v i c e \ P o r t P r o \ D o s D e v i c e s \ P o r t P r o UܓēVW3öh ‰uüÿ4 ‹ø;þ‰=À u
¸š Àéâ€_ ¹ 3ÀSó«ÿ5À jÿ0 ‹=, Eôh€ Pÿ׍EüPVVEôj"PV‹uVÿ( ‹Ø…Û|=¸‚ hÂ_ ‰Fp‰F@‰F8EìPÇF4Ô ÿ׍EôPEìPÿ$ ‹Ø…Û} ÿuüÿ< ‹Ã[_^É S‹\$
UV‹C`3ö‰sW¶‹{
+΄ó j]+Í„è ƒé
…â ‹@
¹P " ;Áw_tR-@ " t9jY+Át"+Át+ÁuYf‹Å_Gîé¯ f‹Ã_‰ ‰Ké¤ f‹fÃ_f‰ ‰ké” f‹ìˆ ÇC é‚ f‹f‹Gfïët-T " tfjY+Át3+Át ÇC
Àë\97uVëÿ5À jÿ0 jÿH PÿD ë3jj]3ɸ UQPÿ@ ;Æt‹ðU¥¥¥P¥ÿ énÿÿÿf‹‹Gï‰s‹s2Ò‹Ëÿ8 ‹Æ_^][ \ D o s D e v i c e s \ P o r t P r o U‹ìQQ¡À …Àt
h PÿP Eøh¬ Pÿ, EøPÿL …À|
‹Eÿpÿ< É Ü R j | ” ª Æ @ î þ . F [O´< Ã_ [O´< 0 ð [O´< * ^ Ãœ R j | ” ª Æ @ î þ . F %IoDeleteDevice !IoCreateSymbolicLink IoCreateDevice dRtlInitUnicodeString ŸKe386SetIoAccessMap 2MmAllocateNonCachedMemory •IofCompleteRequest fMmUnmapIoSpace MMmMapIoSpace Ke386IoSetAccessProcess :IoGetCurrentProcess 'IoDeleteSymbolicLink =MmFreeNonCachedMemory ntoskrnl.exe < Ãœ2æ23
33323=3B3V3f3u3C4K4S4Z4q4ƒ4Ÿ4Ú4ê4ò4ù455 .\i386\PORTPRO.sys È º Ó‚ * Ô G ÐNB10 [O´< N:\2kDDK\i386\PORTPRO.pdb

I have no idea where I got it. And there's no useful information to be gained from the properties screen.