I posted my question on another windows xp forum and got a great answer here:
http://www.computing.net/answers/windows-xp/xp-installed-but-on-boot-asks-to-load-vista-not-installed/201471.html
It looks like my system was originally preconfigured with Vista, but was reinstalled with XP prior to sell since Vista was not the ideal OS. Consequently, the boot up options got screwed up. I ended up using msconfig to do a safe boot with networking in order to delete the desired files.
I currently use a Dell Optiplex 960 which runs windows XP. This is the only operating system that has been installed on it. I recently tried to delete some files, but I found it would require me to start up my computer in Safe Mode first to delete them. However, upon pressing F8 to pull up the option to startup in safe mode, I only get two options: Load Windows Vista (which has never been installed on my system), or run the memory test. When I select the windows vista option, my computer boots up as normal in XP. When I choose the memory test option, I get a message which states that there is some sort of error with a file called "\boot\memtest.exe" with the following status: "0x000000e".
Why is my computer telling me I have Vista installed? And how can I fix it? How can I make it possible for me to bootup in Safe mode again? And how can i fix the memory test issue? Any help would be appreciated. If more details are required, please let me know. Thanks.

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