Splinter cell chaos theory totally confusing starting trouble

the day one i bought my comp amd phenom 2 - 3ghz, and my Graphics card ATI RADEON HD 4650 1 gb , 2 gb -ddr-2- 800
i installed that game...updated with 1.5 euro patch.....over witted the files in ./Data/MAPS and also in ./System ...applied crack ...

and it started running beautifully with highest Graphics mode for 18 days without a problem.....
day before i got a bug in my comp due to some dam reason so i formatted my entire hard disk and re installed my pc again WINDOWS XP...

.installed all my Graphics Drivers, direct x c, etc...and finally Splinter cell CHAOS THEORY...

but if i run now i am getting 2 errors as shown below

so i re-installed my graphics driver once again thrice and also the game thrice ..in all combinations .but same problem exists ....

the error showed by it was

1) Your graphics does not support features necessary to run the game (shader model 1.1 , not available on NVIDIA GeForce 3/ ATI Radeon 8500 or higher).
please contact your graphics card retailer for further information.

2) the instruction at "0x7473af34" referenced memory at "0x0000002c". The memory could not be "read".

click ok to terminate the program

can anyone help me out???...i want the game to run again fine as before....