The Internet connection problems could definitely be the work of the infections.
You will need to disconnect from the Internet for the following fixes (I'd suggest physically unplugging the cable), so you should either print out these instructions or save them into a text file using Notepad.
1. Run HijackThis again, put a check in the boxes next to the following entries, and click the "Fix checked" button:
F2 - REG:system.ini: Shell=Explorer.exe mcafee32.exe
F2 - REG:system.ini: UserInit=userinit.exe,xpjava.exe
O4 - HKLM\..\Run: [Regmgr] scvhost.exe
O4 - HKLM\..\Run: [Microsoftf DDEs ContDLL] rune.pif
O4 - HKLM\..\Run: [PPPOEOE] winlite.exe
O4 - HKLM\..\Run: [Microsoftf DDEs ContrDL] runm.pif
O4 - HKLM\..\Run: [McAfee Windows Protection] mcafee32.exe
O4 - HKLM\..\Run: [Compaq32 Service Drivers] msconfig32.exe
O4 - HKLM\..\Run: [msci] D:\DOCUME~1\YIKYAN~1.ITW\LOCALS~1\Temp\200562817262_mcinfo.exe /insfin
O4 - HKLM\..\RunServices: [Microsoftf DDEs ContrDL] runm.pif
O4 - HKLM\..\RunServices: [Microsoftf DDEs ContDLL] rune.pif
O4 - HKCU\..\Run: [Windows Media Player] mcafe32.exe
O4 - HKCU\..\Run: [Regmgr] scvhost.exe
O4 - HKCU\..\Run: [Norton Personal Firewall] lah.exe
O4 - HKCU\..\Run: [NAV Auto Protect] navprotect.exe
2. Reboot into safe mode (you get to the safe mode boot option by hitting the F8 key as your computer is starting up)
- Open Windows Explorer, and in the Folder Options->View settings under the Tools menu, select "show hidden files and folders", and uncheck "Hide protected operating system files" and "Hide extentions for known file types".
- Locate and delete the following files:
mcafee32.exe
xpjava.exe