Hello, I have got an ATI HD 4850 512MB (GDDR3) which uses this BIOS: - Core: 625.0 MHz - Memory: 993.0 MHz However, after having installed ATI drivers on a freshly installed Windows 7, the card makes the system crash at startup with a BSOD. After a lot of research all over the web I found this thread, whose OP had the exact same problem (and BSOD code, with screen glitches!), but he eventually never tried to fix. So I decided to follow the suggestions in that thread and started downclocking core and memory of all clock states available, with no success. Then I've slightly increased voltage in all clock states. Still no luck. Then, I disabled the card in device manager and started Windows, without any BSOD. With GPU-Z I've found out the card goes to 625 / 993 even if no clock states contained that information anymore. After a lot of struggle I discovered that this clock is defined as "Standard clock" under "Additional features" in RBE. I've read this cannot be easily edited and can only be changed using RBE signatures. So now I haven't got any option left. Is there still anything I can do? Thank you in advance P.s: I remember the card worked great in a similar setup after having increased voltage only (I remember OCCT ran for more than 20min with 0 memory errors!). Then I changed the card with a new one and left it unused for more than a year.