Compaq Presario 6300

I have a Compaq Presario 6300 series desktop. I run many utitities to
keep it safe. I use Zone Alarm Firewall/Spyware, Windows defender,
Lavasoft Adaware Pro and Norton Antivirus. So far things have gone
well. Until last night when adwatch detected some changes trying to
be made to the registry and some things were trying to be installed.
I blocked each attempt. When I went to re-logon a box came on the
screen with some symbols and letters on the header and a box that you
coild type in that said ID. My only option was one button that said
"OK". I tried to ctrl-alt-delete but the box would not go
away. I rebooted and now that same box appears in front of a black
screen BEFORE XP boots to the logon screen. If I click OK, it ill
allow me to logon, but nothing loas in my systray and most of the
icons have changed and look like they are not associated with any
program. I get a message that says 'Cannot find ZClient
(ZoneAlarm)" and gives me a choice to look on the web or browse
for the file. When I click on a program or icon nothing loads. Does
this sound like a virus? Since that "box" appears BEFORE my
logon screen, will a "restore" using my factory restore
discs remove this? TIA

Update: Booted into Safe-mode. The box came up again. I clicked OK. It
continued to load my settimgs. Windowa asked if I wanted to do a
system restore. I said Yes and rolled back 5 days. It then loaded
everything fine. I did a full scan with Zone Alarm and found nothing.
I am about to do a "on-line" scan also. I am not sure what
happened. lol Now I am afraid to reboot. Any thoughts???

Update #2: I was able to get online and do a scan at Trendmicro and
the scan found 1 Cookie. My son went to log on his name and the
"box" came back again. Now I am back to stage one. It has
to be something with my son's profile. It was while he was on his
name that this all started. Will a FULL system restore using the
"Restore Discs" that came with the PC wipe out anything
that was on his name or at least prevent it from
"activating" since his profile will be gone? TIA.

Try making your son a User, not an Administrator.