These are two apparently inocuous applications. nvappfilter.exe is a part of the nVidia ForceWare Firewall, which is shipped along with the nVidia drivers, in case you have an integrated ethernet controller on your nVidia motherboard. utorrent.exe is, well, for uTorrent, the amazingly lightweight BitTorrent client for Windows.

But, if you mix the two, you get a pretty heady cocktail. You end up with memory leaks, CPU overload, window freezes and God knows what not. Memory leaks occur, when due to a bug, an application begins to eat up the remaining free memory you have, till it eventually leads to your system crashing. CPU overload occurs when one process hogs all your CPU power, generally resulting in the rest of your system, including mouse, desktop, etc. not responding.

Well, according to the developers of uTorrent, it’s due to a bug in the nVidia Firewall. I find that not too hard to believe, because many people have flamed the code of that application for various reasons, most of them generally resulting in system instability. They recommend other third-party firewalls like ZoneAlarm.

But, in the FAQ (Frequently Asked Questions) section of uTorrent’s site, they’ve also mentioned that this bug had been repaired in the latest version of the ForceWare Firewall. I’m assuming that they’re referring to the version released with the driver version 6.86.

I think they’re wrong.

I had the old version installed, not 6.86, and I agree, uTorrent and ForceWare were not going hand in hand. I had trouble working with other applications. The mouse would move in a jerky manner. Other applications, especially games, would drop in framerate. Heck, I couldn’t even shut down Windows properly! uTorrent would stop responding, and this would cause me to End Task it. This is not good. Because this means that when I start uTorrent again, it will have to check the non-complete downloads in case any of them got corrupted. This generally takes some time and some CPU time, as in some percentage of the processing power.

Anyway, I installed ForceWare 6.86 for my nVidia 4 chipset. Along came the Firewall which I installed. Technically, they call it the Network Access Manager.

By the way, when you’re dealing with nVidia drivers, it’s advisable to uninstall the earlier version before installing a new version. If you can spare the time, uninstall your display drivers as well!

So, after restarting my PC, I start uTorrent. It’s memory usage starts at a healthy 1 MB or so, but after about 10 minutes, it’s reached 20 MB, which is a clear sign of memory leakage. This means that if I leave the PC on for a night of dowloading, it’ll probably crash my PC. :-O

So, I’m thinking that I’ll uninstall the firewall, because uTorrent is indispensable. Plus, the Network Access Manager, installs along with itself a host of other junk services and processes. For example, it installs the Apache Web Server, because the control panel for the firewall is through the web browser. The Apache processes take up a fair bit of memory. Also, there are a number of other processes for the Firewall, like nTrayFw.exe, which takes up 2 MB, nSvcAppFlt.exe, which is the application filterer for the firewall. The Apache processes take up 6 MB of memory.

I suggest the same to everyone else.