IE 8 slow? This tweak won't help.

sighting Friday, right on the heels of Internet Explorer 8’s release, Ed Bott wrote up a tweak he stumbled upon that he claims sped up a colleague's Internet Explorer 8 installation.

So I checked with a few colleagues on some back channels and discovered a tweak that had worked for other people.  From a Command Prompt window, I had her run the following command:

regsvr32 actxprxy.dll

[…] After restarting her computer, she tried using IE8 again. The results were stunning […]

Since his post, a dozen or so users have chimed in with their successes.

I also have no clue why this is working, but the difference is amazing. If it’s the placebo effect, order me up another case of placebos! - Glenn Blinckmann

I’m tickled with this IE8 speed fix. The speed fixes I have tried in the past for various kinds of software didn’t work as advertised, if at all. This fix though, wow! IE8 is now faster by a factor of 3x for me. That is with only two open tabs, though, so not a scientific test. - Lawrence S. Miller

So what is actxprxy.dll? Well, as Ed pointed out, the library is pretty obscure and has almost zero documentation. The fact it came from back in Internet Explorer 3/Office 97 days doesn’t help either. From what I’ve been able to gather via method of poking, actxproxy.dll is a proxy for software to communicate with out-of-process ActiveX/COM objects. More precisely, to enable communication between Internet Explorer and the Shell.

… and regsvr32? Regsvr32 is a very simple tool that simply loads a binary and calls its DllRegisterServer, DllUnregisterServer, or DllInstall function, depending on the switch you pass it.

I sat down and spent some time disassembling actxprxy.dll… and to no surprise the DllRegisterServer function simply calls NdrDllRegisterProxy with a bunch of interfaces to register. I also conducted a few experiments. First, I exported portions of my registry to file and tried re-registering the DLL. After re-registration, I used WinMerge to compare the two files and noticed zero (relevant) changes. Second, I tried unregistering the DLL. Internet Explorer immediately malfunctioned and ultimately ceased to work at all, indicating the library had to have already been registered.

As a result of some pretty simple testing, I’ve come to the conclusion that reports of success with this wanna-be tweak are no more reliable than the average Bigfoot sighting. That is, people see what they want to see. I did hear from a reader, however, that adding /prefetch:1 to your Internet Explorer shortcut speeds things up wonderfully. *grin*