"explorasi.exe" is a worm/Trojan which your AV or 'nasties scanner' has gotten rid of ... but the entry that's asking it to load at start-up is still on your system, hence the error message.
You will need to edit your registry, back it up first, and remove any entry you find for explorasi
This program is part of Windows, and is used to run program code in DLL files as if they were within the actual program. However, many viruses also use this name or similar ones. This file is also commonly used by spyware to launch its own malicious code.
Note: The rundll32.exe file is located in the folder C:\Windows\System32. In other cases, rundll32.exe is a virus, spyware, trojan or worm!
Strongly suggest you pop along to ... http://www.bleepingcomputer.com/ ... and follow their advice, they are very good at helping people with infections.