Problems With Initial Scans Told To Run

First of all, thank you in advance for your help.
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I was following the instructions of what to do before proceeding, and I had a few problem with the first step running Hijack This.

When it started, it quickly stopped and said I did not have access for some reason. It told me to find the Hijack report and delete them. I pushed "ok". Then the scan resumed.

A huge log came up, with no line item of "HijackThis reports" so I could not delete the report as the instructions say to do. and when I went to save it as "hosts", it told me I did not have access as Administrator to do so, even though I do and am logged in that way. I had to save the huge log of info as a txt file in "My Document"

Since things were not proceeding as the instructions indicated they would, I stopped and am sendin this info to you now to know how to proceed. This computer has been acting very strangely for over a month how, and I am hoping you can help me.

Thank you and I look forward to hearing from you.:)