Windows XP problems

McAfee was giving me problems, so I recently reformatted my hard drive and reinstalled windows XP Home on my Dimension 4400 after backing up all of my files.  I thought this would be an easy - although time consuming task....but little did I know!

After reinstalling Windows XP from my CD, I went to Microsoft's site and updated my OS.  All of the updates are installed perfectly, until I get to Windows XP SP 3.  This SP will just not install.  I've searched all of the forums at Microsoft's website and here, tried most of the solutions posted, but none of them work.  I keep getting the Error Code: 0x8007F0DA.

Then I thought, who needs Windows XP SP3?  So, I went to Adobe and started reinstalling Acrobat Reader and Flash Player.  Flash Player installs, but everytime I try to install the Reader program (whether its v. 7.0 or 9.0), I get "Error 1335: The cabinet file Data1.cab required for this installation is corrupt and cannot be used.  This could indicate a network error, an error reading from the CD-Rom, or a problem with this package."  Of course, clicking Retry does nothing, cicking Ignore gives me Error 2350 "FDI server error", and clicking Abort or Cancel leaves me frustrated and about to throw something at my computer.  Finally, I waived my white flag in surrender, and decided to try installing other programs like my McAfee from Comcast that started this whole episode.  While this program installs, it gives me error messages when I load up the Security Center that seem unfixable.

The first time all of this happened, I chalked it up to bad luck and maybe something going haywire in the installation process.  I have now reformatted my hard drive and gone down the installation process at least 3 times and the problems still persist.  I've tried many many many suggestions that I've seen on the Internet (unregistering and re-registering Windows Installer, downloading the programs and then installing from my hard drive, etc) and nothing seems to work.  I feel like Windows XP is the root of this problem, but I don't know what to do.

HELP!