這個檔名應該是微星MSI顯示卡的DOT動態超頻程式。
不過您系統裡面的檔案是不是病毒，還是要經過掃描才能確認。

Google 一下, 看來不是病毒
http://www.file.net/process/sw20.exe.html

sw20.exe file information
The process sw20 MFC Application belongs to the software sw20 Application or sw20.exe by unknown.

Description: sw20.exe is located in the folder C:\Windows\System32. Known file sizes on Windows XP are 208896 bytes (35% of all occurrence), 212992 bytes, 200704 bytes, 118784 bytes, 69632 bytes.
The program has a visible window. There is no information about the maker of the file. Program starts when Windows starts (see Registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run). It is not a Windows system file. sw20.exe is able to record inputs. Therefore the technical security rating is 27% dangerous, however also read the users reviews.