I've bought a Compaq laptop on XP, when I try connecting to the internet via dialup and the built in modem, the dialup icons says "Un-available device missing". I have updated the drivers from the Compaq website, still happens. Can someone please advise as to what may be the problem and how I can go about fixing it. Thanks.

It cant find your modem. What service do you use for Dial up.

Are there any exclamation marks in Device Manager signifying which device is problematic?

This could also be a "software" device. Is "Un-available device missing" the entire exact message?

XP-Home or XP-Professional?

Service packs installed? Which?

Based upon the above questions, have a look here for possible resolution. If you do find your answer in the provided link, please post back and let us know it's been solved, and by which method/article.

EDIT: Looks like AphJN beat me to it by a couple of minutes. ;>)

XP pro SP2 !

I cant get to the computer until later tonight so will then check for an exclamation mark in the device manager to signify which device may be problematic.

Which section is likely to be suitable for this, there's loads of content they're and it's tricky finding which section/s will be most suitable.

I've copied your Private Message here. Please note, from the Rules page; http://www.d-a-l.com/rules.php
"PLEASE do not contact a moderator, administrator or other member for computer help directly, either by Private Message or email. You will get a far quicker and more comprehensive response by posting your question in the appropriate category on the forum, as it will be read by all members and tech's."

Private Message Contents
Hi, regarding my problem you posted on:

It's a compaq M300, XP pro SP2 !

There doesnt seem to be an exclamation mark, does this definitely mean its software related?

Which section in the link you provided is likely to be suitable for this, there's loads of content they're and it's tricky finding which section/s will be most suitable.
End of PM

As you have more information on this system than I, I provided an "upper level" link so you may narrow things down.

Have you run the system diagnostics on the modem in Device Manager? (Properties, etc.) Query Modem? I think it's called. If the system gets a response from this, the hardware is OK, and it's probably a driver or dll problem. If it doesn't respond to the query, check your bios settings for the elements involved with the modem operation. Comm ports, IRQ, and with a Voice/FAX/Data modem, there will be wav.inf driver files for the voice properties of the modem.