How do I reduce the card speed of the Network Interface Card?

Most any standard PCI NIC will work for you, as long as you have an available port on your PC. Here is one from newegg.com at a great price. It's a Rosewill and I've bought that brand often.
Rosewill RC 404 Ethernet Card 10 100 1000Mbps PCI 1 RJ45

Wikipedia says:
A network interface controller (also known as a network interface card, network adapter, LAN adapter and by similar terms) is a computer hardware component that connects a computer to a computer network.[1]

Early network interface controllers were commonly implemented on expansion cards that plugged into a computer bus; the low cost and ubiquity of the Ethernet standard means that most newer computers have a network interface built into the motherboard.

My guess would be interface. I don't know what mindows is. Neither does the spell checker.

Using arp command (Windows 95/98/NT/2000)
From Windows 95/98 MS-DOS prompt or at Windows NT/2000 command prompt, you can use the arp
command to assign the IP address to the network interface card. It is necessary that TCP/IP is set up
correctly on the computer that will execute the arp command. Perform the following procedure:
1. At Windows 95/98, select [MS-DOS prompt] from the [Start] menu. At Windows NT/2000, select
[Command prompt] from the [Start] menu.
2. Execute the arp command. For example, if the MAC address of the network interface card is
00:11:22:33:44:55 and the IP address to assign is 192.168.0.128, then input as shown below,
and then press [Enter].
(Example: C:\>arp -s 192.168.0.128 00-11-22-33-44-55
3. Execute the ping command for the assigned IP address. In this case no response is returned
from the network interface card.
(Example: C:\>ping 192.168.0.128
4. Turn off the main power supply to the print controller and the main body printer, then turn it
back on.
Chapter 2 Setting Up the Network Interface Card
2-4 Konica Network Interface Card INSTRUCTION MANUAL
A Status Page will be output. Check that the IP address is correctly set in the list. Or, when about 5
minutes have passed after having restarted the print controller and the main body printer using the
ping command, check that the network interface card responds correctly. The ping command is also
executed at Windows 95/98 MS-DOS prompt or Windows NT/2000 Command prompt. The example
of executing the ping command is shown below:
(Example: C:\>ping 192.168.0.128

Using arp command (UNIX)
From UNIX you can use the arp command to assign the IP address to the network interface card.
Perform the following procedure:
1. Turn off the print controller and the main body printer.
2. Log in as superuser on a host on the same subnet as the network interface card. However, if
the server resides on another subnet, complete this procedure to store the IP address in the
network interface card.
3. Find the MAC address of the network interface card. The address is printed on the Status Page
each time you turn on the print controller and the main body printer.
4. Edit the hosts file (usually /etc/hosts) or use NIS or DIS to add IP address and node name of
the network interface card. See the network administrator for the IP address. For example, a
network interface card with a name of printfast and an IP address of 192.9.200.200 has the
entry:
192.9.200.200 printfast
5. Add an entry to the arp cache for IP address and Mac address of the network interface card,
as:
arp -s 192.9.200.200 0:40:c8:0:0:ff
RS6000 (AIX) requires the ether option after arp -s. For example:
arp -s ether 192.9.200.200 0:40:c8:0:0:ff
6. Check the print controller and the main body printer to see that the network interface card is connected
to the network. Turn on the print controller and the main body printer.
7. Send a ping command to the network interface card to verify it is running on the network, as
for example:
ping 192.9.200.200 or ping printfast
The network interface card will not respond to this ping command but it will read its IP address
from the packets.
8. Turn off the print controller and the main body printer and back on again and then send the
ping command again to verify that the network interface card obtained its IP address. A confirmation
message displays as:
192.9.200.200 is alive
9. Remove the entry from the arp cache using the following command. Specify the network
interface card either by its IP address or by its name, for example:
arp -d printfast
Konica Network Interface Card INSTRUCTION MANUAL 2-5
Chapter 2 Setting Up the Network Interface Card
Using MAP
By using MAP (Management Access Program) included the CD-ROM that comes with the network
interface card, you can automatically identify the network interface card on the network and set it up
for TCP/IP by using Web Utilities. To use this method to assign the IP address to the network interface
card, the following procedure should be performed on computers in advance:
• TCP/IP correctly configured
• IPX/SPX-compatible protocol installed
• MAP installed and MAP setup correctly executed
About how to set up TCP/IP and how to install IPX/SPX-compatible protocol, refer to Windows Help
menus for example. For MAP, refer to “Using MAP (Management Access Program)” in this chapter.
To change an IP address already assigned to a network interface card, you can not use the
arp command. Use Web Utilities instead. These methods also allow you to set up subnet
mask and default gateway, etc.
Using NIManage
Refer to “Chapter 7 AppleTalk Configuration”.

Accessing Web Utilities
The network interface card is provided with an HTTP server having Web Utilities. By accessing this server,
you can change settings of the printing system. There are two ways to access Web Utilities, through a Web
Browser, either through Netscape Navigator, version 4.x or greater or through Internet Explorer, version 4.x
or greater.
• Use MAP to have the network interface card on the networks identified automatically, thereby accessing
Web Utilities.
• Use a Web Browser to type the IP address assigned to the network interface card, and thereby access
the Web Utilities. For example:
http://192.168.0.128/
If you designate the proxy setting in your Web Browser you cannot access the Web Utilities.
For more information see your network adminisrator.
Chapter 2 Setting Up the Network Interface Card
2-6 Konica Network Interface Card INSTRUCTION MANUAL

Using MAP (Management Access Program)
A utility called MAP is provided on the CD-ROM that comes with the network interface card.
This program automatically identifies the network interface cards on the networks and lists them on Web
Browser screen. From this Web Browser list you can select a network interface card to change its settings
and control Web Utilities.

You need to go into device manager (control panel, system, hardware, device manager). Under Network, highlight your network interface card, right click and select uninstall. Once it's uninstalled, reboot your computer and it will automatically install it again.

Go into device manager (control panel, system, hardware, device manager). Under network connections, right click your network interface card and select uninstall. Reboot the computer and it will automatically reinstall.

Is your lan card supports Giga? If not, this is the cause of disconnection, some routers does not supports older version of hardwares and softwares. If you have latest version of software on the routers, you should also update the driver of your Network Interface Card. Giga does not support a 10/Half-duplex interface, 100/Half-Interface but does support 100/Full-duplex or 100/Auto, you can check if your Network Interface Card is properly configured to these by doing these:

1.) Right click on "My Network Places" desktop icon.
2.) NIC Properties
3.) Configure
4.) Advanced
5.) Media Type/Speed and Duplex

I suspect that the network interface card failed, & that's why you get the error message. Try disabling it from the BIOS & see if the error message disappears. If it did, then you have a failing network interface card & need to install anew one.

To Reduce the link speed of your adapter to 10 half duplex, click Start | Control Panel | System | Device Manager | Network Adapters -> your NIC card properties ->Advanced Tab -> Link Speed = 10mbps half duplex.