I have Windows 95/98/Me/NT/2000/XP/2003, can I use WLAN Optimizer?
The tool was developed for Windows Vista. However, it also works with Windows 7, Windows 8, Windows 8.1 and Windows 10.

There is a slight chance that it works on Windows XP SP2 with KB918997 and on Windows XP SP3. Both of them support the Native Wifi API (which is the API WLAN Optimizer uses). VC++ Runtime or/and the actual .NET-Framework is/are required.

How to install WLAN Optimizer?
Extract the zip package into a directory of your choice and launch the executable file. However, the path must not contain any special characters like "è, ê, é, ü, ä, ö, ..." or else the autostart option probably won't work.

Best Practice: Just activate the Disable background scan tweak and leave the other tweaks untouched. If you experience problems, you can also try enabling streaming mode. Disabling autoconfig is notrecommended (it's pretty much the same as disabling background scan, but you won't see any wireless networks in Windows). 

I get a "side-by-side configuration" error at startup!
Probably you have to update your .NET-Framework.

"Start with Windows" doesn't work!
If your WLAN Optimizer path contains special characters (è, ê, é, ü, ä, ö, ...), the autostart option probably won't work. There are four options to solve this issue:

• install Service Pack 1 for Windows Vista
• manually correct [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
• install the program in a directory without special characters
• let the program start from "Start Menu\Programs\Startup"

How to uninstall WLAN Optimizer?
Run WipeOut.reg from install folder (it removes registry values set by WLAN Optimizer) and after that delete the WLAN Optimizer folder. 

WLAN Optimizer starts fine, but it doesn't work!
First of all, there has to be at least one connected wireless adapter. If you have a stable connection and experience just one lag per minute, try another combination of tweaks. Sometimes just disabling background scan doesn't work. Additionally enabling streaming mode can help. Every user has to find out the best combination for himself by trial and error. I recommend disabling background scan first. If this doesn't help try a combination with the other tweaks. If there isn't any working combination for you, you should try another driver. One user reported driver version 2.1.0.0 as a solution for problems with his RT61-chipset and WLAN Optimizer 0.10 Alpha.

If the lags appear more often than every 60 seconds or they appear not periodical, probably they aren't the result of Windows background scan activity. In this case WLAN Optimizer can't help (the lags seem to be caused by a bad signal / instable connection).

Do I need WLAN Optimizer?
Maybe not. One user told me that by using the latest Ralink driver there was no lag at all. He said: 'I would like to let you know that the latest Ralink rt73 drivers have a built-in solution for the lag spike problem. Since Vista version 3.1.2.0 and XP version 1.2.4.0 of the rt73 driver there is an option called "Smart Scan". If you enable that, the lag spike is gone.'

What is Streaming Mode?
According to MSDN the WLAN driver won't "implicitly perform any self-initiated actions that may decrease packet throughput over the media stream. For example, the driver must not initiate any network scans or radio power management on its own" while streaming mode is active.