According to Wikipedia:
"Nullsoft Scriptable Install System (NSIS), is an open source, script-driven Windows installation system with minimal overhead backed by Nullsoft, the creators of Winamp. NSIS has risen to popularity as a widely used alternative to commercial products like InstallShield."

If you install WinAmp, it uses that instead of the InstallShield. Maybe WinAmp left it when it got installed.

In my opinion, one man's spyware is another man's legitimate business tool.

When I last looked, Norton labelled third party tracking cookies "spyware" -- which are the cookies we all use when referring ccBill sales, or practically any other sales lead to a shopping cart on a website -- so that we can get paid.

Because of this, I do not use Norton for anything. I wouldn't worry to much over "NSIS" ... there's much more sinister stuff out there, like GAIN / Gator / Screwy Toolbars.

Steve