MPREXE.exe -- What is this?

I run a software firewall on my machine at home and frequently get alerts that this is trying to access the internet from my machine. I generally block it, and see no efects.

The file resides in the Windows/System directory on my home and office PCs.

What is this program intended to do? I didn’t find anything immediately helpful on the Symantec or Mircosoft sites about it.

I had a problem with MPREXE quite recently; the problem is apparently most often related to .pwl file (password lists) and indeed my problem began when an existing machine was taken over by a new user, logging in under a different identity, however, in my case, nothing short of a Format C: and reinstall would make it go away and believe me, I tried everything.

You’ll find MPREXE quite well covered at

that is to say that the problem is most often related to corrupted .pwl files.

But apparently can be caused by driver conflicts, particularly with HP printers, and by a few odd things in Novell Netware.

MPREXE.exe is one component of the Windows Networking Service Multiple Provider Router (MPR). Basically, in all Win32 OS versions, the MPR is responsible for forwarding file system requests to each registered network provider to determine whether it is able to process the request. (A Windows network provider has nothing to do with Internet Service Providers – it’s simply a suite of network client software that’s been installed and registered on the machine). What this means is that when you or a program running on your machine attempts to access a file, the MPR hands the filespec to each network provider that’s installed on your system and asks whether it can fulfill the request. If it says yes, that request and subsequent ones for that resource are directed to that network provider. This is one of the key components that allows Win95/98/NT/2000/ME to transparently have several types of network connectivity at the same time – the MPR is responsible for figuring out which one does what.

Getting rid of it won’t solve any problems, it’ll only make a bigger mess and nearly ensure that you’re going to have to reinstall Windows. A problem that manifests itself as a hang or crash in MPREXE.EXE, MPR.EXE, or related modules is often a result of misconfigured network component, a problem with a password list file (*.pwl), or something else that causes a hang or crash when the MPR attempts to query each of the network providers. Short of a reinstall of the OS, you can always attempt to remove each network client component in turn until the problem goes away, then attempt to reinstall that component.

Experienced network developers and support techs will recognize that I’ve oversimplified horribly and glossed over some details that are critical to understand if you’re developing or supporting Windows network software, but that don’t materially affect end users.


Its not causing any problems with my machine that I can recognize. Occasionally I’ll get a firewall alert saying the MPREXE is doing something. Occasionally I permit it, usually I block it. I don’t notice anything when it does one versus the other.

If this device only talks to the network conponents on my machine why might it trigger a Firewall alert?

It makes me a little nervous if something that accesses my .pwl is bringing up firewall messages.

Thanks again.