It's difficult to say from here without more information, but the things I'd look at are:
Are the two machines the same - does the slower machine have less memory, slower hard drive, slower processor or different software? Are the files being transferred to the main drive of the computer - for example, FAT is much slower than NTFS so if download to a FAT formatted memory stick, it will be a lot slower. Are both PCs connected in the same way? (if one is wireless connected and the other using a cable, the wireless will be a lot slower).
Are there any errors being reported for the Ethernet connection on the PC?
Wireless routers can be connected via an ethernet cable in the same way as wired routers. If the second router has a client mode feature then the routers can also be connected wirelessly otherwise the second router will only function as a wireless access point.
second, it will still see the first but will not receive any dhcp info from it
There are two common problems. First one, you forgot to install drivers for the wireless adapter. Second one, your router is secured and requires a key to connect. You have get the key from other computers in your network or connect to the router using a LAN cable and change the key.
Routers perform DHCP, which means the router acts as the "owner" of the network. If a router set it's own IP address to 192.168.1.1, then it will likely assign IPs to computers connected to it in the 192.168.1.x range. If you plug another router into your first router, the second router might have the IP 192.168.2.1, and then assign IPs in the 192.168.2.x range. This is what you want to avoid. Having all your computers on the same 192.168.x network is necessary. You essentially want to use your second router as a switch. To do this, disable DHCP in the routers admin UI. Then, instead of plugging the source cable (coming from your first router) in the "Uplink" port, plug it into one of the regular 1, 2, 3, 4 etc ports. This will enable your router to pass along IPs from your main router, rather than assign it's own. Plug other devices into 2, 3, 4, etc. You've essentially bridged your routers.
Yes. Viruses attack a computer. Anti-viruses defend a computer. Pending on your router, there is usually a Firewall on your Router. I would not bide on that for half a second though. The cost of buying an Anti-virus program for 3 computers almost always comes with discounts, or you can find a good free one. I'd suggest: Microsoft Security Essentials.
If you have a wireless router just get a wireless adapter for the computer. It can be USB or PCI adapter. And connect your new adapter to the router in the same way as you connected the first computer.
Routers have to be configured because computers are by definition "stupid". What I mean by this is that computers do only what people program or tell them what to do. A router is programmed to communicate and transfer data between computers. If you don't tell or configure the router what devices to communicate with, it will draw a big question mark and do nothing. Routers have come a long way in the past several years, making it fairly easy to set them up, and most companies (like linksys) will help you set up your router if you are unsure of how to do so. Even so, they still have to be configured so they can do what they are designed to do, ROUTE!
A cascaded router because is a router connected to another router. As far as I know, there's two ways you can connect two routers together. One is from a LAN port to the WAN port of the other router and the other is LAN port to LAN port. LAN to WAN is useful for things such as network segmenting, say that you want the LAN of the first router not to be able to see the LAN of the second router. That can work. Whereas with the second way, the second router pretty much becomes a switch and you can have access to devices on both networks without the need for port forwarding. Consider it acting as a swithc with a IP address pretty much. However in this method you have to make sure the LAN IP of the second router is within the same subnet as the first in order for this to work. So let me give you a example of how it can be setup: LAN to WAN: Router A WAN IP: Issued from ISP (Usually through DHCP) LAN IP: 192.168.1.1 Subnet Mask: 255.255.255.0 Router B WAN IP: Issued from the DHCP server of the first router or can be statically set to be a address within the first routers LAN LAN IP: 192.168.2.1 Subnet Mask: 255.255.255.0 Note: With this method, computers on Router B can connect to devices on Router (including the router itself) but not vice versa. Also...you cannot access computers via NetBIOS names (computer names) in this setup. You have to access them by their client LAN IP LAN to LAN Router A WAN IP : Issued from ISP (Usually through DHCP) LAN IP: 192.168.1.1 Subnet Mask: 255.255.255.0 Router B WAN IP: Not used since nothing is connected to the WAN port LAN IP: 192.168.1.254 Subnet Mask: 255.255.255.0 Hope this helps you out. :)
There are two cases. First one is because your router is configured to use one of open ports for internet connection. Second is your router has to be replaced if the fact bothers you.
You need to configure the server as a router or a default gateway. Or you can connect the switch to the modem and all other computers you can connect to the switch including the server. The second part is easier but if you want to control internet on your server you have to use the first part.
First, you must understand the reasons that you would add a router to your network. The main reason is security. A router can add IP masking, as well as better firewall protection. This security is applied over all the computers connected to the network. Second, the ability to add more that just one computer to your network. Especially if you don't use a modem, a router can multiply your speed and efficiency when adding more computers. Third, wireless connectivity. If you get a router, make sure you get one with wireless capability. This way you can use a special adapter (included on most laptops) to connect to your network from rooms away, without wires. This is still very fast and secure, as long as you password protect your home network. So it is appropriate to add a router if you are concerned about security, you want to add multiple computers to your network, or if you need the ability to connect to your network wirelessly.
Basically, the more antennas you have the faster your network can perform. Say you have 10 computers on your network with one router that only has one antenna. That one antenna is sending and receiving the requests for ten computers. when you incorporate additional routers, there are more antennas to manage the load from the ten computers. Also, if you set up a second wireless router as an access point in a different location than your primary router, you can double your wireless range.