I've been having worsening slow performance for ages but always managed to put up with it. However, in the last week my PC has taken a dive. When I click the shortcut, Firefox can take anywhere up to 2 minutes to open and load my homepage. Once online, I can navigate the internet with relative ease and speed but every couple of minutes, Firefox will freeze for a couple of minutes and not allow me to do anything. I have uninstalled Firefox and reloaded it to no effect and it seems to happen with my other browsers too. During the writing of this message, it has frozen twice totaling 3 minutes or more of freeze. All that I have installed recently is GIMP, a free image editing software, and I have uninstalled various old games totaling 4GB (KOTOR 1 & 2 among others) that I no longer need but this issue keeps happening. I share the PC with my mum who is also having problems. It's an old machine (my pleas for a newer one fall on deaf ears) but not old enough to be giving me problems. I have tried doing a system restore to 4 separate points in time but it is unable to do this for reasons it doesn't explain.

Anyone got any ideas what might be going on and if so, can they help? It's now stopping me from attacking on here and it's driving me mental!

i would recommend a fresh install of windows. Just make sure you backup important files first.  It will make it run like when you first got the computer.

I doubt my mum has the discs and I wouldn't confidentally know what I was doing. I'd need a external hard drive to back up the files anyway wouldn't I?

If you have a cd burner you could burn them to a disc or you could put them in a zip and email them to yourself.  Or just upload them to the cloud.

Have you tried defragmenting your hard drive? It used to work wonders for me.

Multiple times. The thing that annoys me the most is the system restore not working.