Windows XP on 224mb of RAM .... I dunno but you could be cutting it fine there, I thought 256 was the minimum recommended, although I looked at the Microsoft site and they stated;

Here's What You Need to Use Windows XP Professional (I know you said Home version but .....)

* PC with 300 megahertz or higher processor clock speed recommended; 233 MHz minimum required (single or dual processor system);* Intel Pentium/Celeron family, or AMD K6/Athlon/Duron family, or compatible processor recommended
* 128 megabytes (MB) of RAM or higher recommended (64 MB minimum supported; may limit performance and some features)
* 1.5 gigabytes (GB) of available hard disk space*
* Super VGA (800 × 600) or higher-resolution video adapter and monitor
* CD-ROM or DVD drive
* Keyboard and Microsoft Mouse or compatible pointing device
I think they might be a little optimistic or misleading, while it might run on a machine of the specifications above, I think anyone trying it will be bitterly disappointed. My experience with XP is that is is fairly resource hungry and really loves 512mb RAM or more - I gave it the flick and went back to Windows 2000 on one of my desktops, best move I made.

You may want to consider Windows 2000 if you can, just as good as XP in my opinion, just not dressed in the fancy clothes. I have friends running W2K on 256mb RAM machines flawlessy after having similar problems with XP.

Check for spyware as suggested, but also when the computer is running slow do a Ctrl-Alt-Del and have a look at Processes in Task Manager - you may see what is chewing up the resources that could be causing the slowing of the machine. This may help find and remedy the problem, and if the budget extends that far, throw in some more RAM - your Windows machine will love you for it

Good luck.