XP Error 633: device already in use. Both dial-up and VZAccess Manager

OK, guys.  I've tried everything I can think of and researched til I'm blue in the face.

This is a laptop with XP home (was SP3, but I reverted it back to SP2) and Verizon Wireless (USB Modem) and VZAccess Manager.

This is my Mom's laptop and she discovered that the Verizon Wireless stopped connecting and brought the computer to me.  It would just stick on initializing or it would say the com was already in use.  I later discovered that the dial-up modem has the same problem.

I do NOT think it is the problem with either the USB modem or the dial-up modem since they are both having the same problem.  I believe it is part of Windows that is damaged or something that is causing this.

Any ideas????  I'm stumped!

Thanks for any help!


Who is Participating?
BeerAngelConnect With a Mentor Author Commented:
OK, I found the solution.  Wow, am I pissed, but also relieved.

What caused this, was a false positive by f-prot antivirus that attacked necessary files that were introduced by SP3.  

Here's a thread on it:

Problem solved, and thanks for all who gave input.  This one ate my lunch!
Start with the error logs. The problem with using these wireless broadband mobile cards is they require you to use the software which is always extremely resource heavy and very often causes all kinds of system errors and makes other components not work properly. After checking the error logs, you might think about checking the firewall settings and how the VZAccess manager is clashing with it. If all else fails try removing the verizon software and reinstalling it.
what is the model no and brand of your laptop, please inform.

Improve Your Query Performance Tuning

In this FREE six-day email course, you'll learn from Janis Griffin, Database Performance Evangelist. She'll teach 12 steps that you can use to optimize your queries as much as possible and see measurable results in your work. Get started today!

BeerAngelAuthor Commented:
MSRamrod: I don't think the firewall will interfere with dialing...only with data transfer post-dialing.  I do however agree the VZAccess Manager could be causing the problem....but was it that or a Windows update that suddenly caused an incompatibility?  I don't know.

I have uninstalled and reinstalled the Verizon software at least 5 times.  To no avail.  I even tried to dial without VZaccess Manager installed and still I get the Error 633 message.

What logs are you referring to?  Location of them?

mail2prabir: Dell Inspiron 1300.


Thank you both!

download latest drivers for your laptop and install them. avl at

it should solve your problem. if not revert back
BeerAngelAuthor Commented:
mail2prabir: I did, but didn't help.  My gut feeling is that this IS a Windows problem, possibly caused by VZaccess Manager or an update.  It is not a modem failure or driver problem.
BeerAngelAuthor Commented:
OK, update.  Get this!!!!

My Mom has 2 computers, one desktop and one laptop.  She brought the desktop over and it's doing the EXACT same thing.  These computers where networked together by me a while back and all was working well, until recently.

Virus, or update?  I've scanned the laptop and it only showed spyware.  Thoughts?
it is worthwhile to eliminate malware possibility, is your system has SP3 installed? if not try it on one system and revert back
BeerAngelAuthor Commented:
SP3 is on both systems.  I did revert the laptop back to SP2 and still no good.
Here's a fix that worked for me.  I'm on a Lenove laptop with a PC5740 Air Card
Find the NEC PCI to USB Open Host Controller
Choose Roll Back Driver.  You will probably get a message saying there isn't any driver to roll back to.
When I clicked OK, it re-enabled the device.
VZ Access Manager relaunched and recognized the card.

Hope this helps.
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.