Hi Lora and welcome to Daniweb forums :).
I have to say that I have not seen the about:blank infection for a very long time. When did you acquire it?
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Can you please do the following.
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Can you disable Windows Defender as it may interfere with the removal process. Please leave it disabled until your PC has been given the all clear.Open Windows Defender
Click Tools
Click General Settings
Scroll down to Real Time Protection Options
Uncheck Turn on Real Time Protection (recommended)
After you uncheck this, click on the Save button
Close Windows Defender
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Scan with HijackThis and then place a check next to all the following, if present:
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://hsremove.com/done.htm
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://hsremove.com/done.htm
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
O3 - Toolbar: (no name) - {300BC64A-BF32-4cc8-8917-91148CEFE700} - (no file)
Now, close all instances of Internet Explorer and any other windows you have open except HiJackThis, click "Fix checked".
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After rebooting, rescan with hijackthis and post back a new log.