Minecraft - Fatal Error!

Hi, guys!

I keep getting this fatal error and I'm unable to play Minecraft - here's the message I get each time I load Minecraft Launcher....

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Bootstrap (v5)
Current time is Feb 8, 2014 10:31:05 PM
System.getProperty('os.name') == 'Windows 8'
System.getProperty('os.version') == '6.2'
System.getProperty('os.arch') == 'x86'
System.getProperty('java.version') == '1.7.0_51'
System.getProperty('java.vendor') == 'Oracle Corporation'
System.getProperty('sun.arch.data.model') == '32'

Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 2/10)

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 3/10)

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 4/10)

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 5/10)

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 6/10)

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 7/10)

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 8/10)

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 9/10)

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 10/10)

Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.

Unable to download remote file. Check your internet connection/proxy settings.

FATAL ERROR: net.minecraft.bootstrap.FatalBootstrapError: Unable to download while being forced
at net.minecraft.bootstrap.Bootstrap.execute(Bootstrap.java:95)
at net.minecraft.bootstrap.Bootstrap.main(Bootstrap.java:381)

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This is really annoying me - please could you help!

Most appreciated,

Alex