Computer repair shop owner here. Tips and advice:
1 Yes you need to upgrade or replace your XP machines. The security issues will prevent you from logging into your bank or purchasing things online.
2 You can not upgrade from XP to 7. You will need to save your data and do a clean install.
3 If you machine has a dual core processor (or better) and 2 GB of ram it will run great and you will be a happy camper. Microsoft says you can get by with a much slower processor and only 1 GB of ram, but it will not be a pleasant experience.
4 For Windows 8 users. Check out a program called “Classic Shell” it’s free (you can donate to the developer and I do every time I install it on a customers computer). It allows your windows 8 machine look and act like Windows 7 or XP.
I have an old compaq desktop. Intel Celeron 2.70GHz 376MB of RAM. Will win7 run on my machine?
It only makes the Start Menu look close to older systems. You still have to play peek a boo to find other functions. One interesting thing Classic Shell restores is "Hibernate". What makes many persons including myself loathe 8 is several unnecessary annoyances. Mandatory "Cloud" for one especially if on metered usage. The hiding of needed system settings on the bottom right. The annoyance is you have to play hide and seek and they often pop in in scrolling a page. The default X BOX Video player stinks. No "X" to close it. Yet another go to the corner and see if it's there annoyance. I like to have never got IE to allow me to open a window in a normal size. I got the one third screen compressed screen.
W 8 was poorly vetted among users. It seems the Tablet users were the BETA testers. The OS is designed mainly for accommodating Tablet users but not with long time desktop users in mind. Last is things like their default Mail Client. It stinks but Mr Haney at MS will now "Rent" Outlook to you in a high cost full package deal per year.
Yes long time MS customers had good reason to be angry. In all aspects except maybe security W 8 is a huge downgrade from what previous OS offered up through W 7. It seems more like the beginning of an Internet Slum Lord program. Most things you had before included you can now rent at the mercy of Corp MS. Meaning they can end your access to said app at any time.