Someone who has openly suggested they aren't confident with a computer is hardly going to rebuild the machine or install Ubuntu...
Chrome seems to be your biggest concern at the moment. Chrome should automatically install Flash updates, so you won't need to manually install anything. You can see if your Chrome can be updated, which it probably can if you haven't used it in over a year. Open Chrome > Menu (looks like a burger!) > Settings > About and from there you can see if it can be updated - chances are it will update itself.
When you start it up/shut it down are you getting any update/configuring messages? I would agree with whoever said above that your machine is probably way behind on updates. In the evening, go to Control Panel > Windows Update > Check for Updates... This will probably take a while but come back to it after 30-45 minutes and see what it has found. You can let it update and leave it to run through the night.
However, if you have done this and it appears to get 'stuck' then you may want to try installing them in smaller batches i.e. when it searches for updates and shows available updates, you can tick/untick what you want it to install. Might be best to try it in smaller batches. One of my users had this issue a few weeks back, and it was one update amongst 68 that was killing the machine and preventing it from updating. I just did it in smaller batches to try and narrow down the fucker. I would normally wipe and rebuild to be honest but it was his home computer, not his work computer, and he stuff on there he needed, so I played the long game. Took about 4/5 hours as they machine was dreadfully slow but the updates were preventing him from accessing the internet and doing anything, really. 4/5 hours but I only had to do something for a few minutes every half hour or so.