I was able to find the item in services.msc. I tried Autoruns as suggested earlier, but could not find anything there. I disabled it there, but on Windows 7 there is no such startup item. When I installed on XP there is a msconfig item called 'Asus USB-N13 WLAN Control Center'. In my case, I need AP mode so I need the software, but I don't want the Control Center to auto start since it's useless until I plug in the dongle. If your hardware does not have AP mode, then I suggest trying to uninstall the Control Center altogether, but leave the drivers installed & see if you can use it with the Windows wireless software. Though I agree that the Control Center software is redundant to the native Windows wireless software, it's necessary in 'AP' (access point) mode. I don't know the specific details & features of your Asus PCE-AC68 wireless, but my dongle is capable of serving as a wireless access point in addition to being an Ethernet client. The hardware may be a different model, but because it's the same brand, I assume that the software is the same albeit branded under a slightly different name. The software is called 'Asus USB-N13 WLAN Control Center'.

I landed on this page because I have an Asus USB-N13 wifi dongle bundled with software that presented the same problem on Windows 7.

Asus pce ac68 error windows 7