Vince, actually a router can also help a single computer network. Depending on what the user does, it can be used to help filter out some of the inbound stuff that the ISP doesn't catch and that can cause your system to slow down (offload some of the firewall activity from the computer to the router) as well as be a wireless point for people who can't reach their modem from the same room as their computer (some people have to have their modems right beside their demarcation point).
That said, I believe Shaun's problem is related to something else. Unfortunately there are so many different variables to consider before we really diagnose the problem. Stuff that I would suggest (and doing it in this order is recommended):
1) Back up any personal data (photos, emails if you keep them on system, word and excel documents, etc., business records if kept on this computer)
2) Flush out your temporary internet files cache (this varies with whichever web browser you use)
3) Use programs like CCleaner to delete temp files (please do not use the registry cleaner unless you know what you're doing)
4) Scan for viruses/spyware/adware using spybot, malwarebytes, anti-virus (you do this after clearing files so it's faster)
5) Running chkdsk (do not do this unless you know what you're doing as you can kill the operating system) to locate cross-linked or corrupted files
6) Running a defrag
This should catch MOST of your issues. There are a couple of other possibilities you could experiencing (for example, you can try to uninstall and reinstall QQ). There are so many ways of doing things (I could write a book on the subject) that this is really only a general guideline.
Hope it helps.
