I have an Antivirus 2008 software file on my computer and can't delete it. It does a free
scan but will not remove any infections/viruses w/o purchasing. Several times it has
blocked my navigation to the internet. While trying to delete this error message
appears:

Cannot delete antvrs.exe. Access is denied. Make sure disk
is not full or write-protected, and that the file is not currently
in use. What does "disk full and write-protected" mean?

Program was located at c:\Program Files. I moved it to MY Documents.

Help!

You can not remove all installed program parts by "just" moving them to another directory or bin. Installed programs have to be de-installed via "start" , "configuration" , "software" , selection and delete. Re-install the same identical software once more, and than remove it the proper way.
With removing software like you did you run the risk that Windows still looks for parts of the software, can't find them, and start causing all kinds of problems.
Although there are other ways to correct the problem you experience now, it requires understanding of Windows and what can be removed and what not.

Good free Anti-Virus software is AVG.