I turn on my launcher, no problem, i run minecraft 1.8.1 ( i tried others too) minecraft window opens, mojang log appears, theres a crash, it goes back to launcher with error report as shown below:

[10:10:34] [Client thread/INFO]: Setting user: shia123
[10:10:34] [Client thread/INFO]: (Session ID is token:a13bf56bb5e542f0a6ce1fbefe48de65:1581ca3be5064a19afbf38a21b62b47e)
[10:10:37] [Client thread/INFO]: LWJGL Version: 2.9.1
[10:10:37] [Client thread/INFO]: Reloading ResourceManager: Default
[10:10:38] [Sound Library Loader/INFO]: Starting up SoundSystem...
[10:10:38] [Twitch authenticator/ERROR]: Could not authenticate with twitch
java.net.UnknownHostException: api.twitch.tv
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184) ~[?:1.8.0_25]
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[?:1.8.0_25]
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[?:1.8.0_25]
at java.net.Socket.connect(Socket.java:589) ~[?:1.8.0_25]
at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:649) ~[?:1.8.0_25]
at sun.security.ssl.BaseSSLSocketImpl.connect(BaseSSLSocketImpl.java:173) ~[?:1.8.0_25]
at sun.net.NetworkClient.doConnect(NetworkClient.java:180) ~[?:1.8.0_25]
at sun.net.www.http.HttpClient.openServer(HttpClient.java:432) ~[?:1.8.0_25]
at sun.net.www.http.HttpClient.openServer(HttpClient.java:527) ~[?:1.8.0_25]
at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:275) ~[?:1.8.0_25]
at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:371) ~[?:1.8.0_25]
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191) ~[?:1.8.0_25]
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1103) ~[?:1.8.0_25]
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:997) ~[?:1.8.0_25]
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177) ~[?:1.8.0_25]
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1511) ~[?:1.8.0_25]
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1439) ~[?:1.8.0_25]
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254) ~[?:1.8.0_25]
at uk.a(SourceFile:250) ~[1.8.1.jar:?]
at dar.run(SourceFile:85) [1.8.1.jar:?]
[10:10:38] [Thread-6/INFO]: Initializing LWJGL OpenAL
[10:10:38] [Thread-6/INFO]: (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
[10:10:38] [Thread-6/INFO]: OpenAL initialized.
[10:10:39] [Sound Library Loader/INFO]: Sound engine started
[10:10:41] [Client thread/INFO]: Created: 512x512 textures-atlas
#

1. A fatal error has been detected by the Java Runtime Environment:
   #
2. EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x27723e88, pid=3516, tid=5676
   #
3. JRE version: Java(TM) SE Runtime Environment (8.0_25-b18) (build 1.8.0_25-b18)
4. Java VM: Java HotSpot(TM) Client VM (25.25-b02 mixed mode windows-x86 )
5. Problematic frame:
6. C [ig4dev32.dll+0x3e88]
   #
7. Failed to write core dump. Minidumps are not enabled by default on client versions of Windows
   #
8. An error report file with more information is saved as:
9. C:\Users\shia\AppData\Roaming\.minecraft\hs_err_pid3516.log
   #
10. If you would like to submit a bug report, please visit:
11. http://bugreport.sun.com/bugreport/crash.jsp
12. The crash happened outside the Java Virtual Machine in native code.
13. See problematic frame for where to report the bug.
    #
    AL lib: (EE) alc_cleanup: 1 device not closed
    Java HotSpot(TM) Client VM warning: Using incremental CMS is deprecated and will likely be removed in a future release