something seriously wrong with my pc!!

me again ....

anyway a while back i had a virus on my pc so decided to reinstall windows and start afresh, well now my pc is very slow and keeps disconnecting from the internet (im using a 3g dongle) so i presumed it was the dongle and bought a new one and getting the exact same problems, it seems to be getting worse and worse could you please check my log it seems very short im presuming its due to reinstalling windows recently (about 3 weeks ago) could you look throguh it please, and if theres nothing there any tips and suggestions would be greatly appreciated.....thanks

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 3:34:16 PM, on 4/15/2009
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)
Boot mode: Normal

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\userinit.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\MSN Messenger\MsnMsgr.Exe
C:\Program Files\3\3Connect\AutoUpdateSrv.exe
C:\Program Files\WinZip\WZQKPICK.EXE
C:\WINDOWS\system32\wscntfy.exe
C:\Program Files\3\3Connect\Wilog.exe
C:\Documents and Settings\Administrator\Desktop\hijackgpthis.exe

O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - Global Startup: Update Agent.lnk = ?
O4 - Global Startup: WinZip Quick Pick.lnk = C:\Program Files\WinZip\WZQKPICK.EXE
O16 - DPF: {C3F79A2B-B9B4-4A66-B012-3EE46475B072} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab56907.cab

--
End of file - 1410 bytes

I notice that you never scanned with an Antivirus previously before starting this thread - because you don't even have an Antivirus installed!
This is somewhat suicidal in today's digital world.
That's why I want you to install one first!!

* Please install Avira Antivirus: http://www.free-av.com/
This is a free Antivirus.

Perform a full scan with Avira and let it delete everything it is finding.
Then reboot.
After reboot, open your Avira and select "reports".
There doubleclick the report from the Full scan you have done. Click the "Report File" button and copy and paste this report in your next reply.
Then we'll start from there, because it really makes no sense otherwise that we clean this up manually if an Antivirusscan is not present which should be able to deal with most and prevent further reinfection.

oh god im downloading it and its downloading at a speed of 5kb/sec and it will take 2 hours to download a 28 mb programme? there must be something seriously wrong with my computer, will get back to you if and when its done.....

i could not download that anti virus as it kept cutting out, i have reinstalled windows and nothing, i keep getting an message saying "win32 generic encountered a problem and had to close" i had this exact same problem with my laptop, everything is awfully slow and most of the time becomes unresponsive when loading something and internet keeps disconnecting do u know what the problem could be im starting to think its very serious...

Unless you can get an AV active, there isn't much I can do if this is an infection, but without an AV, there's no defence.