Well I found something on McAfee Support Forums that explains your problem exactly. I am going to post the response in here but might take few post to get it all in here.
Welcome to our forum!
After looking around the forum I found some manual uninstall instructions to get rid of the firewall from your system. Follow the instructions below and see if you can get out of your safe mode loop. This situation is most odd. After you uninstall empty your temporary internet files (say yes to off line content), runscan disk and defrag. Let us know how it goes and what you wish to do next.
Backup the registry.
From the taskbar, click Start.
Type regedit and click OK.
The Registry Editor appears. From the menubar, click Registry.
Note: If using Windows XP, click File.
The Export Registry File dialog box appears. In the 'Save in' drop-down menu, select Desktop.
In the 'File Name' field, type backup.
In the 'Export range' section, select All.
Note: To restore the registry, double-click on the backup file you just created and follow the prompts. After completing all of these steps and verifying that everything is working properly, delete this file to avoid restoring the old registry.
Highlight my computer at the top and than click on edit.
Than click on Find and search for MpfBocks.VxD and delete all reference found. The search will stop on the first file found. You will have to hold CTRL and tap "F" after you delete each file found to continue the search until it says, "finished search through the registry.