Zzz when i play dota ,my comp will suddenly restart itself.when i change my grafic card(ge force 9500),my comp also continue wif tim problem.what happen to my comp??

Forget about installing XP.
Dota 2 Minimum requirements are:

CPU Speed:Dual core from Intel or AMD at 2.8 GHz
RAM:4 GB
OS:Windows 7 or newer
Video Card:nVidia GeForce 8600/9600GT, ATI/AMD Radeon HD2600/3600
Sound Card:DirectX Compatible
Free Disk Space:15 GB

Incompatible system/hardware.Not a clean install.Bad grafic settings.Dirty CPU radiator/fun.Cheap power supply.Obsolite grafic card.Bad drivers.Missing components updates.Bad CD support/player.

I think will have to lower the screen resolution in order for your TV to handle the video signal. Maybe 640x480 or maybe 800x600. That is if your TV is a traditional CRT tube TV (not a flat panel).

Yes that one option, remove the video card and try cleaning the video card pins with an eraser. return it back and make sure it it is properly attach. if the problem continues then clean also the memory with an eraser. if still continues then try removing the processor then return it back, this refreshes the processor of the computer.

grafics drivers hp 9500

kindly cheak your moniter EHT

It sounds like the frequency referred to is the monitor's frequency. If it's an LCD monitor, the frequency is usually 60Hz. If you are using a VGA cable, it's guessing the frequency and has guessed wrong.
The other possibility is that the Railroad Tycoon game sets the screen resolution and frequency to something your monitor is not capable of displaying. It sees a nice graphics card and shoots the settings to the top of the range. If you can change the settings before playing the game, you might get it to work.

go to your bios set &check sata hard drive is it enable or disable change it to disable

yap dota from warcraft III

yes , there a few steps to take for this
1.right click on the desktop
2.click on the settings tab.
3. make sure that the graphics adapter driver is installed if not it will say plug and play adapter
4.if the adapter is installed continue with step 5
5.click on the colors drop down menu and choose the highest possible colors ... usually 32 bit...
the problem could be.. that you are using an older monitor that does not support higher colors then what you are achieving at the moment.. consult your hardware documentation for that information of maximum colors per pixel.