If you see a blinking line in the upper left corner,that indicates that HDD tryes to read the boot sector in order to start loading OS,but for some reason fails.That can be due to the partially damaged boot sector,damaged or messed up sectors on which boot sector is stored to or simply a bad HDD,but hopefuly that's not the case with you.But be sure to fix that problem as soon as possible otherwise one day OS will not boot at ALL.If you do not know how to fix that,let us know and we will tell you how.
So if some of your HDD sectors are screwed up,that can cause your screen to freeze during some specific activities when a graphic chip tryes to read a specific driver function for a specific activity such as watching videos which has been stored on a corrupted HDD sector and therefore it cannot read that graphic function from corrupted sector(s) in order to provide the neccessary execution showed on your screen and that is why your screen will freeze because your graphic chip simply does not know what to do next.
Of course it can be other reasons too.If the graphic chip is overheating,it will cause things like videos to work slow as hell or not work at all lol.The GPU temperatures should NOT be above 60!
Also be sure that the video files you are watching are not damaged or that the location they are stored to IS readable.You can use CHKDSK commands to check that and fix errors if neccessary.Here is the syntax:
CHKDSK C: /f /r
"C:" is the driver letter you want to check.You can also check just the specified location on your HDD by writing the path to the location you want to check if you want,without checking the entire HDD,but it is recommended to check the entire HDD just in case.
Also try to go to your graphic driver options/settings/configurations or how ever you call that and from there restore the default factory settings,save that and then restart your computer.Also try to turn off options such as deinterlacing and all other modes such as Bob in the video player program you are using to play video files...for example VLC.
Also be sure that the options in the video player you are using are correctly adjusted.If you are not sure about that,let us know what player you use so we can help you or simply if you can LOAD DEFAULT VALUES if possible.
By the way if by any chance you touched any graphic options in the BIOS,revert them back or load optimal defaults if you do not know how to revert them back.
And of course be sure that your system is virus-free.
You also mentioned that your sony drivers are not recognizing Windows 7 64-bit.In this case be sure that you download drivers for the 64-bit (x64) version of Windows and NOT the 32-bit (x86) version of Windows.Once you have downloaded them,first uninstall ALL other graphic/display drivers and THEN install the new ones you just downloaded and after that restart the computer.
Try the above suggestions and let us know if it fixed your problem.
Cheers!
