The only solution I have found that dramatically enhances call quality and reduces drops for Skype calls is to set the process priority for Skype.exe in Windows to “Above Normal” or “High.” This is accomplished by using the Windows Task Manager (Control-Alt-Delete) and going to the “Processes” tab. Here you will find all the programs and services running on your computer. Highlight “Skype.exe,” then right click on your mouse to bring up a context menu and select “Set Priority” and then select “Above Normal” or “High” (do not select “Realtime”). I have tested both settings and haven’t noticed a difference between the two, but this may depend on your particular system setup. Then close out the Windows Task Manager. After doing this, you should see a noticeable improvement in your Skype calls, especially Skype Out calls to landlines and cell phones. Increasing the process priority for Skype did not appear to affect the performance of any my other programs or otherwise slow down Windows in any way.
The only drawback to this solution is that the process priority for Skype.exe will revert back to “Normal” when you reboot your computer. In order to force Windows to save Skype.exe’s process priority to “Above Normal” or “High,” you need to use a third party utility. I have successfully used the free utility program called Prio – Process Priority Saver. You can download it from http://www.prnwatch.com/download.html. After installing this program, it will add an additional menu item to the “Set Priority” context menu in Windows Task Manager described above, which is entitled “Save Priority.” After you select the process priority you want for Skype.exe (“Above Normal” or “High”), select the “Save Priority” menu item below it and a check mark will appear indicating that the process priority you selected will be saved permanently, even after a Windows re-boot. You can always modify these settings later on if you want.