Can you please do the following.

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Scan with HijackThis and then place a check next to all the following, if present:


R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://red.clientapps.yahoo.com/cust.../www.yahoo.com

O2 - BHO: (no name) - {E7E6F031-17CE-4C07-BC86-EABFE594F69C} - (no file)

O4 - HKUS\S-1-5-18\..\Run: [msiexec.exe] msiconf.exe (User 'SYSTEM')


Now, close all instances of Internet Explorer and any other windows you have open except HiJackThis, click "Fix checked".

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Locate and delete the following item(s), if present. Make sure you are able to view system and hidden files/ folders:

Search for...

msiconf.exe

...using "Start | Search...".

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Note that some of these file(s)/folder(s) may or may not be present. If present, and cannot be deleted because they're 'in use', try deleting them in Safe Mode by doing the following:

• Restart your computer
• After hearing your computer beep once during startup, but before the Windows icon appears, press F8.
• Instead of Windows loading as normal, a menu should appear.

Select the first option to run Windows in Safe Mode hit enter.

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Reboot.

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After rebooting, rescan with hijackthis and post back a new log. Please let me know how your pc is now.