Help please my dad's computer won't load up

My Dad has a dell dimension with xp software and for no reason when it loads up now, all you get is a blue screen where normally the user accounts appear but am getting nothing but an hour glass and it will not allow any further access to the pc, has anyone got any ideas.

i have unplugged and replugged it all but still no joy.

 

Swalesy,
Try safe mode to see if it atelast boots, then we (MG members) can troubleshoot further from there.

Just before you see the WindowsXP splash screen with the green or blue dots moving across the screen on the bottom, hit the F8 key. You'll have to figure out at what point this occurs for you, but it's the time between the POST and when the SPLASH SCREEN appears. The menu that comes up will have all sorts of options. Choose the one that says "Safe Mode Without Networking" by selecting its' respective number and hitting enter.
Let us know if you boot into safe mode.

 

Many thanks will try this tomorrow and get back in touch.