McAfee virus scan's System Scan takes a lot scanning at the startup

I'm running Windows 2000 Pro in my desktop computer under NTFS . I recently installed McAfee virus scan v.5.20 with the scan engine
4.1.40 . Them problem I'm having is happening during the startup . When I turn on my computer and I log on into Windows .
My hard disk takes a lot of time spinning, well, it loads all desktop icons and the taskbar icons, but after I get all desktop icons in their places; the hard drive keeps spinning for 3 or 4 more minutes . I was suspecting about the antivirus system scan, so I right clicked on it and I selected its properties and I saw it was still scanning my hard drive , specifically the C:/Winnt folder . It took like 4 or 5 minutes to end that task .
How can I decrease the time it takes scanning my hard drive . I'd like to start working on my computer inmediately the desktop icons are in their places .
Under Windows Me, McAfee virus scan never took a lot of time at the beginning scanning the hard drive . So I don't know why it is taking too much time at the startup .
Any suggestions for decreasing the time of that hard drive scan will be appreciated .

PS : where is the MSCONFIG option on Win 2K?
note : my computer is 96MB RAM, 10.2GB hd
and Celeron 466MHz .

Make sure Vshield is NOT configured to scan all files. It should be set to scan selected extensions only like COM, EXE, DLL, DOT, DOC, VBS, etc...