Ethernet connection vanished! Wireless still ok

Hi, Thanks for reading my post.
I hope this hasn't happened to anyone else, but in case it has, I'd love your advice on how to restore ethernet capability on my Sager.
In late Jan 08 the ethernet went out on my Sager 3880, running windows xp pro.
The Network Connections and the Device Manager now only show 1394 Net Adapter (firewire connection) and the Intel (R) PRO/Wireless 2915ABG Network Connection, no ethernet!
There are hidden files in Device Manager that seem to pertain to the ethernet:
Direct Parallel,
Generic Marvell Yukon Chipset based Gigabit Ethernet Controller - Packet Scheduler Miniport , and
Generic Marvell Yukon Chipset based Gigabit Ethernet Controller #2 - Packet Scheduler Miniport.
The Properties tab for each of the three drivers shown above lists "Location: Unknown".
Not sure if the #2 is supposed to be there--I used the disk of drivers to try to reinstall the Marvell driver before I saw that any ethernet related drivers were in the hidden files.
Besides the wireless and infrared devices listed in the device managers hidden network adapter files are: RAS Async Adapter and five WAN Miniport Adapters.
Do I have any devices missing? Do I have any redundancies? Any ideas on how to restore ethernet capability?
I've googled ALL of the entries pertaining to this topic, searched Microsoft's update support site to see if one of their "critical" updates could have caused the problem, checked IPCONFIG to see if the ethernet stuff was listed there (it wasn't), so I've run out of ideas on what to check next. Oh, yes, I've tried making a new network connection and also tried just plugging in the ethernet cable and hitting new hardware to see if the sager will find and install ethernet capability,...long shots, I know, but I'll try anything. Any ideas??? Thanks!!!

Thanks for writing back. Yes, I scanned for hardware changes but none came up in the device manager.
Then I went to Sager's web site and downloaded the driver for ethernet for the 3880 which is the Generic Marvell. I think that's why I have 2 listed in my device manager now. It only shows up in the device manager as a hidden file, not an active one and isn't present at all anywhere else in my system. Any other ideas?? Am wondering if I have to do a system restore to get the ethernet capability back?

I tried to do that but I got the message from the Device Manager " Failed to uninstall the device. The device may be required to boot up the computer." I'm very puzzled as to how to remedy this situation and think I may have to contact Sager to see what they suggest.
Thanks for your writing back and for the advice--at least it validates that the things I've tried weren't entirely off-base!

Tried system restore but all it did was get rid of the second marvell miniport scheduler that I'd mistakenly added in. So the restore theoretically brought me back to square 1 and a point where everyting worked, but it didn't.
Decided not to mess with the BIOS just yet and took the easy way out--dug up an old Linksys ethernet cardbus adapter. Installed it and it works like a charm--just hate the look of the little brick sticking out the side of the Sager, but the ethernet speed is 2X the speed of my wireless, so it is well worth putting up with it.
The new adapter shows up as "Local Area Connection 2" but there is still no sign of my original Connection 1. If I ever get it sorted out how to revive/reinstall the original ethernet connection, I'll repost.
Thanks for all your help in the meantime!