On my PC, why am I having network problems after installing file-sharing software?

Peer-to-peer Internet file-sharing programs (for example, BitTorrent clients such as uTorrent, Gnutella network clients such as Shareaza, and ED2k clients such as eMule) often slow a network connection or cause network problems, such as error messages or the inability to connect to other resources, because they use up bandwidth. If you transfer only a few files, you may not notice any problems, but when you share several files at once, your networking performance may dive sharply.

At times, you may experience these problems even when you're not intentionally sharing files, because many file-sharing programs are configured to launch in the background every time you log into your computer, and so you may be sharing files unknowingly.

Furthermore, some peer-to-peer file-sharing programs include third-party software that can also affect your network performance or corrupt your computer's networking components. Many third-party programs are spyware, adware, or malicious programs such as keyloggers and Trojans. They take up bandwidth in reporting back to the programmer or another compromised computer, and in some cases set your computer up to be part of a botnet, which causes a slowdown.

Also, the peer-to-peer networks these programs connect to contain much malicious software (aka malware) masquerading as desired files. While the presence of this software doesn't necessarily slow your connection, the software's actions (infecting your computer and subsequently propagating themselves) do.

If you experience network problems after installing file-sharing programs, follow these steps:

1. Disable the file-sharing program from starting automatically. How you do this depends on the program, but in many cases, if there's no setting within the program to reconfigure this, all you have to do is:
   
   
   1. Click Start, then Programs or All Programs, and then Startup.
   2. Locate the file-sharing program, and then right-click it. Select Delete.
   
   
2. Remove the third-party accompanying programs, and/or run security software to remove infections. Keep in mind that this sometimes renders the file-sharing program dysfunctional.

It is impossible for UITS to compile an exhaustive list of potential malware and all the third-party applications that, while not malicious, still affect network performance. The following security packages available from Indiana University detect most problematic third-party programs accompanying file-sharing programs:

Symantec AntiVirus

While Symantec AntiVirus exists primarily for virus, worm, and Trojan removal, it also detects and quarantines or removes spyware, adware, and other types of malware.

Windows Defender

Windows Defender is Microsoft's antispyware program. It is available as a stand-alone product and as part of Windows Vista. It can scan for and remove spyware components from your computer's memory, registry, and hard drives.

Also see:

• What is Symantec/Norton AntiVirus software, and where can I get it?
• In file sharing software, how can I disable outbound file sharing?
• What is Ad-Aware, and where can I get it?
• In Windows, how do I edit the registry to remove New.net?
• What is Windows Defender and how do I use it?