It sounds like your power supply might be failing.  Do you leave your system plugged in?

 

 

Thanks for reply.

 

I plug it in in the morning, plug it out at night. Should I buy a new power supply then? Can I do that?

 

Took a good half hour to work this morning. I'm just waiting for the day it won't switch on at all.

This is your problem.  Computers aren't meant to be unplugged.  By being plugged in and turned off it uses less than one watt.  If you're worried about an electrical store get a quality surge suppressor.  Try leaving it plugged in and if that doesn't do the trick you can always get a new power supply.  If it's under warranty contact Dell and if not there are many sources for Dell power supplies.

 

 

Just an update:

 

I left my PC permanently plugged in and everything worked fine for about 2 weeks, but then one day the computer just wouldn't switch on at all - no reaction.

 

So I bought a new power supply, put it in, and now everything's working as good as new.

 

Thanks for your help!

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eimear wrote:

Just an update:

 

I left my PC permanently plugged in and everything worked fine for about 2 weeks, but then one day the computer just wouldn't switch on at all - no reaction.

 

So I bought a new power supply, put it in, and now everything's working as good as new.

 

Thanks for your help!

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I'm glad to hear you got it working :).  Sometimes it seems like if something can break it will break.  :P