Vista - Boot Problems and powerdown

I have begun to experience problems with MESH machine. Time and time again it will just switch off. When trying to reboot I get 2 different messages either;

1) Options on how to boot safe, networking etc due to hardware changes

or

2) That windows did not shutdown correctly and how should i reboot

Sometimes the machine will fully boot and remain power up for perhaps 30 mins sometimes no more than 5 secs.

This can happen whether I try do actually use the machine or even if I do nothing.

When it does boot up after choosing an account to log on "PLEASE WAIT" can be on screen for up to 10 minutes before I see desktop.

I did recently upgrade my graphics card to an ATI Radeon x1950 Pro with 512mb but this worked perfectly for over a month before the problems have started.

What I have noticed is that If i do manage to get beyond 20 mins and accept updates from windows update (what I thought maybe the problem) updates will download OK but as soon as they attempt to install BANG off she goes.

Any advise would be greatly appreciated. I am not very tech minded and if further information is required please advise where to find it and I will add to this post.

Many Many Thanks

Mark

Mark

Have you tried a system restore to a point before this started happening?

John

John unfortunatly I have but to no avail

Regards
Mark

if u have replace your cpu or a fan, i would suppose its the thermal paste, but normally you computer would only be on for a maximum of about 2 mins for that..but ur gettn about 30 mins

Do you mean it powers down, or literally just switches off.

Literally Switchs Off

Have you checked the error logs after one of these shut downs?

Are you doing anything in perticular when it switches off. Is it gfx intensive. What wattage is your psu. How old is your computer. Have you checked your error logs under computer management? When was the last time you cleaned the inside, The fans can get clogged up with dust and it does change the thermal dynamics of your computer.

what size power supply you have and is it generic or good one? sounds like power supply to me because i had same thing happen to me recently after hardware upgrade. check your rails for the power supply i bet they are dipping pretty bad

I agree with the above, but check what I said on my previous post. You can check your voltages in the bios.