regarding winstart001.exe This is not a virus or trojan. The application may be removed by running an uninstaller, found on IGetNet's website:
http://www.igetnet.com/downloads/uninstall_igetnet.asp.
Network Associates -- Update October 17, 2003 --
This detection was reclassified from trojan to potentially unwanted program as the author's intentions are not malicious. This change is reflected in the 4299 DAT files.

This file may come bundled with another program, which discloses the fact that it is ad-supported. Users agree to have this program installed in the license agreement, although they may not realise at first that this particular file was packaged with the product they installed.

When executed, two files called WINSTART001.EXE and rules.dat are dropped into C:\Windows\System

This trojan installs the IGetNet application (WINSTART001.EXE is already detected as IGetNet application).
most antivirus are ineffective against spywares/adwares. I suggest you scan you computer with Ad-Aware or Spybot . and also with CWShredder