hijacked

Hello, I cannot open anything on my computer unless I go to run as and click on the box that has a checkmark under "User Account"; Current user and then under that, "Protect my computer from unauthorized program activity." If I don't do that and I click on something, for example, Firefox... I get a message in a box that says: "Windows cannot access the specified device, path or file. You may not have permissions to access the item."

Below is the file requested:

Logfile of Trend Micro HijackThis v2.0.3 (BETA)
Scan saved at 4:22:45 PM, on 2/25/2010
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP3 (6.00.2900.5512)
Boot mode: Normal

Running processes:
C:\WINDOWS\System32\smss.exe

I am doing my best to get what you need. I hope that this is enough for your help. Thank you for anything you can do.

Sheri
C:\WINDOWS\system32\csrss.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\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\LSI SoftModem\agrsmsvc.exe
C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
C:\Program Files\Bonjour\mDNSResponder.exe
C:\Program Files\Spyware Doctor\BDT\BDTUpdateService.exe
C:\Program Files\Canon\IJPLM\IJPLMSVC.EXE
C:\Program Files\Java\jre6\bin\jqs.exe
C:\Program Files\Common Files\LogiShrd\LVMVFM\LVPrcSrv.exe
C:\Program Files\Spyware Doctor\pctsAuxs.exe
C:\Program Files\Spyware Doctor\pctsSvc.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Spyware Doctor\pctsTray.exe
C:\WINDOWS\System32\svchost.exe