I cannot get rid of Win32.virut

According to anti-virus Avast! I have Win32.virut in my computer and it has infected many system files (only *.exe files).
My OS Vista is gradually crashing. Is there a way of removing the virus without reinstallation of Windows (I heard this also is not alwasy successful)? Please help...

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 23:11:14, on 3. 4. 2009
Platform: Windows Vista SP1 (WinNT 6.00.1905)
MSIE: Internet Explorer v7.00 (7.00.6001.18000)
Boot mode: Normal

Running processes:
C:\Windows\system32\Dwm.exe
C:\Windows\Explorer.EXE
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\ESET\ESET Smart Security\egui.exe
C:\Program Files\Toshiba\FlashCards\TCrdMain.exe
C:\Program Files\DrWeb\SpIDerAgent.exe
C:\Program Files\DrWeb\spiderui.exe
C:\Program Files\Windows Sidebar\sidebar.exe
C:\Program Files\Synaptics\SynTP\SynTPHelper.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Users\Peter\Downloads\hijackgpthis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.google.sk
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.sk/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Microsoft Internet Explorer
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
O1 - Hosts: ::1 localhost
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: Java(tm) Plug-In SSV Helper - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre6\bin\ssv.dll
O2 - BHO: QUICKfind BHO Object - {C08DF07A-3E49-4E25-9AB0-D3882835F153} - (no file)
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O3 - Toolbar: (no name) - {BFC32E1D-EE75-4A48-BC60-104E11EE2431} - (no file)
O4 - HKLM\..\Run: [TPwrMain] %ProgramFiles%\TOSHIBA\Power Saver\TPwrMain.EXE
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [Reštartovať program Flash Cards] C:\Program Files\Toshiba\FlashCards\TfcRst.exe
O4 - HKLM\..\Run: [egui] "C:\Program Files\ESET\ESET Smart Security\egui.exe" /hide /waitservice
O4 - HKLM\..\Run: [SpIDerAgent] "C:\Program Files\DrWeb\SpIDerAgent.exe"
O4 - HKLM\..\Run: [SpIDerNT] C:\PROGRA~1\DrWeb\spiderui.exe /agent
O4 - HKCU\..\Run: [Sidebar] C:\Program Files\Windows Sidebar\sidebar.exe /autoRun
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /detectMem (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-19\..\Run: [WindowsWelcomeCenter] rundll32.exe oobefldr.dll,ShowWelcomeCenter (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /detectMem (User 'NETWORK SERVICE')
O8 - Extra context menu item: Append Link Target to Existing PDF - res://C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEFavClient.dll/AcroIEAppendSelLinks.html
O8 - Extra context menu item: E&xportovať do programu Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office12\EXCEL.EXE/3000
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\Office12\REFIEBAR.DLL
O9 - Extra button: (no name) - {BFC32E1D-EE75-4A48-BC60-104E11EE2431} - (no file)
O9 - Extra button: ICQ6 - {E59EB121-F339-4851-A3BA-FE49C35617C2} - C:\Program Files\ICQ6.5\ICQ.exe
O9 - Extra 'Tools' menuitem: ICQ6 - {E59EB121-F339-4851-A3BA-FE49C35617C2} - C:\Program Files\ICQ6.5\ICQ.exe
O13 - Gopher Prefix:
O15 - Trusted Zone: *.ukf.sk (HKLM)
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: Ati External Event Utility - ATI Technologies Inc. - C:\Windows\system32\Ati2evxx.exe
O23 - Service: avast! Antivirus - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: ESET HTTP Server (EhttpSrv) - ESET - C:\Program Files\ESET\ESET Smart Security\EHttpSrv.exe
O23 - Service: ESET Service (ekrn) - ESET - C:\Program Files\ESET\ESET Smart Security\ekrn.exe
O23 - Service: @%SystemRoot%\system32\PresentationHost.exe,-3309 (FontCache3.0.0.0) - Unknown owner - C:\Windows\Microsoft.Net\Framework\v3.0\WPF\PresentationFontCache.exe (file missing)
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: McAfee Real-time Scanner (McShield) - Unknown owner - (no file)
O23 - Service: McAfee SystemGuards (McSysmon) - Unknown owner - (no file)
O23 - Service: PDAgent - Raxco Software, Inc. - C:\Program Files\Raxco\PerfectDisk10\PDAgent.exe
O23 - Service: PDEngine - Raxco Software, Inc. - C:\Program Files\Raxco\PerfectDisk10\PDEngine.exe
O23 - Service: TOSHIBA Optical Disc Drive Service (TODDSrv) - TOSHIBA Corporation - C:\Windows\system32\TODDSrv.exe
O23 - Service: TOSHIBA Power Saver (TosCoSrv) - TOSHIBA Corporation - C:\Program Files\Toshiba\Power Saver\TosCoSrv.exe
O23 - Service: TOSHIBA Bluetooth Service - TOSHIBA CORPORATION - c:\Program Files\Toshiba\Bluetooth Toshiba Stack\TosBtSrv.exe
O23 - Service: TOSHIBA SMART Log Service - TOSHIBA Corporation - C:\Program Files\TOSHIBA\SMARTLogService\TosIPCSrv.exe
O23 - Service: SecuROM User Access Service (UserAccess) - Unknown owner - C:\Windows\system32\UAService.exe

--
End of file - 6025 bytes

Nope, game over.
If we mess around trying to fix it, it will probably mess up the boot manager and then you won't have any OS to use.

Don't back up any exe/scr/php/htm/html/asp files, then format the machine.

Thanks for yur advice, but I have already tried to cure infected system files and after that my PC could not boot again, so I have formatted disk and reinstalled Windows. Now everything seems O. K.