Slow DSL speed!!!!!!!!!

I have Earthlink 3.0mbps DSL, and a netexcell router... i get 600k connections on my main computer(1) (which is this one) and my other computer(2) downstairs, i get 2.8mbps... and whenever a friend bring their computer over 2.8mbps.... This is a custon built computer and never had problems with it.. i have literally talked to Earthlink support for a combined > 5hrs... those people are idiots and make me wait long periods of time, to evaluate my problem, only to finally say something... "please wait longer, thank you!!" lol.... i have been looking all over the internet for about 2 weeks now, with no luck... so i decided to turn to this form for some help... i have changed all wires.... changed network cards.... diconnected other computers... disconnected the router and ran the comp straight from the modem, still no avail.... i always get around 600k.... the speeds were tested with 2wire.com and cnet.com. very frustrated since my friends come over and get speed 4x as fast as mine... again please help!!!!!!!!!!! and thanks....

computer(1) is as follows...
2.0ghz AMD Athlon 64 3000+
1.5 Gigabytes of Ram
120 GB WD HD
MSI NForce 4 PCIe MS-7315
Diablotek Nvidia GeForce 6600GT PCIe 16x
650 Watt Power Supply

Here is mty HiJack this log:
Logfile of HijackThis v1.99.1
Scan saved at 12:55:46 AM, on 4/30/2006
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)

Running processes:
C:WINDOWSSystem32smss.exe
C:WINDOWSsystem32winlogon.exe
C:WINDOWSsystem32services.exe
C:WINDOWSsystem32lsass.exe
C:WINDOWSsystem32svchost.exe
C:WINDOWSSystem32svchost.exe
C:WINDOWSsystem32nvsvc32.exe
C:WINDOWSSystem32svchost.exe
C:WINDOWSExplorer.EXE
Crogram FilesLavasoftAd-aware 6Ad-watch.exe
C:WINDOWSsystem32RUNDLL32.EXE
Crogram FilesAIMaim.exe
Crogram FilesXfireXfire.exe
Crogram FilesMozilla Firefoxfirefox.exe
Crogram FilesWinampWinamp.exe
Crogram FilesMozilla Thunderbirdthunderbird.exe
Cocuments and SettingsThe Dirty ShiznoDesktopMaintenanceHijackThis.exe

R1 - HKCUSoftwareMicrosoftInternet ExplorerMain,Window Title = xMercyful28x
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - Crogram FilesYahoo!CompanionInstallscpnyt.dll (file missing)
O4 - HKLM..Run: [Tweak UI] RUNDLL32.EXE TWEAKUI.CPL,TweakMeUp
O4 - HKLM..Run: [Ad-watch] Crogram FilesLavasoftAd-aware 6Ad-watch.exe
O4 - HKLM..Run: [NvCplDaemon] RUNDLL32.EXE C:WINDOWSsystem32NvCpl.dll,NvStartup
O4 - HKLM..Run: [nwiz] nwiz.exe /install
O4 - HKLM..Run: [NvMediaCenter] RUNDLL32.EXE C:WINDOWSsystem32NvMcTray.dll,NvTaskbarInit
O4 - HKCU..Run: [AIM] Crogram FilesAIMaim.exe -cnetwait.odl
O4 - Startup: Xfire.lnk = Crogram FilesXfireXfire.exe
O6 - HKCUSoftwarePoliciesMicrosoftInternet ExplorerControl Panel present
O8 - Extra context menu item: &Yahoo! Search - file:///C:Program FilesYahoo!Common/ycsrch.htm
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:PROGRA~1MICROS~3Office10EXCEL.EXE/3000
O8 - Extra context menu item: Yahoo! &Dictionary - file:///C:Program FilesYahoo!Common/ycdict.htm
O8 - Extra context menu item: Yahoo! &Maps - file:///C:Program FilesYahoo!Common/ycmap.htm
O8 - Extra context menu item: Yahoo! &SMS - file:///C:Program FilesYahoo!Common/ycsms.htm
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:Program FilesJavajre1.5.0_06binssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:Program FilesJavajre1.5.0_06binssv.dll
O9 - Extra button: Yahoo! Services - {5BAB4B5B-68BC-4B02-94D6-2FC0DE4A7897} - C:WINDOWSsystem32shdocvw.dll
O9 - Extra button: (no name) - {9819CC0E-9669-4D01-9CD7-2C66DA43AC6C} - (no file)
O9 - Extra button: AIM - {AC9E2541-2814-11d5-BC6D-00B0D0A1DE45} - C:Program FilesAIMaim.exe
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:Program FilesMessengermsmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:Program FilesMessengermsmsgs.exe
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:Program FilesYahoo!Commonyinsthelper.dll
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://update.microsoft.com/window [...] 2342368140
O20 - Winlogon Notify: WRNotifier - C:WINDOWSSYSTEM32WRLogonNTF.dll
O23 - Service: Adobe LM Service - Unknown owner - C:Program FilesCommon FilesAdobe Systems SharedServiceAdobelmsvc.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:WINDOWSsystem32nvsvc32.exe

I have checked out portforward.com in the past to try and fix the problem... the problem that i have with it, is that i can't figure it out... the evaluation for it doesnt allow me to actually use the program, so i dont know if it will fix the problem or not... if you will, please give me some more information on how to run the program, or maybe their is just something that i am missing on the site... thx