[WillZZZ]

The core root of your problem is that a virus infected your windows installation and partition and has corrupted some critical files needed to boot. winlogon.exe is an core component in 2000/XP controlling the Windows username/password authentication and if that is corrupted your boot fails. Your son installed or your running off the liveCD Ubuntu which is a Linux distribution and it's helpful in recovering files from Windows partitions. The reason Ubuntu is showing as "read-only" is because the default NTFS drivers in Ubuntu are read-only. You have 2 options of fixing your Windows installation:
1. Get really technically in-depth and fix the Windows installation manually by replacing the files and seeing what's up (there are many ways to do this and I can list many off the top of my head but it gets really complex.) (and this eventually doesn't fix all the problems as the virus is still dormant in your corrupted Windows installation's files and registry and that's another story/step.)
2. Use Ubuntu, copy off all your important files onto a flash disk/drive or burn the files or send it to another computer over the network AND then reformat the computer (starting fresh which is a good thing when it comes to Windows sometimes.) and reinstall Windows and then copy back/reinstall your files.

Depending on your skills, time and complexity I say for your situation do #2. You will have a fresh start in terms of the OS (Windows is clean with no viruses, spyware, malware, etc.) and you can install anti-virus, anti-spyware and whatnot and hopefully practice some safe computing skills (updating the definitions of those apps, etc.)

I kinda agree with your son as I would want to try to get my parents to run Linux but its not for everyone the the learning curve is sometimes steep for those that don't understand computers on a deeper level. Anyways those are my suggestions. Hope your computer is fixed ASAP.