hi i have linux ubuntu 12.4 lts and it has sarted freezing on me
 

i keep having to reboot my computer its freezing my softwear center is not working or my update center. it wont let me go back to my last version and it wont even let me put windows back on it can anyone help please.

Wait, why can't you put Windows back on? The Windows installation is done outside of any OS, so if that's locking up then it sounds like you have a hardware problem, not a software problem.

Have you been making changes to your sources list?
What graphics driver?
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When you say freeze do you mean absolutely no response from the system at all?

I had that happen to me about 10 years ago. The system would freeze, the clock would not change (if the system froze at 3:00, it would still say 3:00 at 9:00), the mouse would not move, and hitting caps lock did nothing. Ultimately, that was a faulty power supply.

i am not sure why windows wont load it keeps saying somthing about not having promission and the grub.. and yes its a 100% freeze and the more i use it the worse it gets.. its not hardwear i have gave it a 120% check its the os that keeps locking up.. its acting like windows that has a worm in it.. i cant even yous the command line half the time. so how can i just wipe the drive and start over.. every thing i have tried keeos sayinn you dont have promission..

Have you been making changes to your sources list?
What graphics driver?
Post output of
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That sounds to me like a power supply issue. If you have one handy, pop another power supply in there for a day or two- I'm willing to bet the problem goes away.

no i havent made any changes to the sources list but i think when i was gone for wor my kids got to it and did something to it... it only works in guest mode... and its a laptop so i dont have a powersuply problem..

Even in a laptop you still have a power supply- it is just intergrated into the system. However, on a laptop replacing it would be a major production/more trouble than it is worth.

I would run Htop in terminal and see what is running that should not be running.

It probably would not hurt to reset bios to default settings also.