First of all memory speed depends on the chipset. The speed has to be supported by front side bus (FSB).
For example the FSB would support may 1066Mhz but the memory 1333Mhz. In such case the memory would be clocked down to 1066Mhz.
Also the usage of different modules is not risky but the faster module would be clocked down to the same speed of the slowest module.

Your notebook belongs to the Toshiba European series. So you have to use the drivers from Toshiba European driver page. There is an driver for the X500 PQX33E series: Intel Turbo Boost Technology v 1.2.0.1002

The Intel Turbo Boost Technology automatically allows processor cores to run faster than the base operating frequency if it's operating below power, current, and temperature specification limits. So you don’t need to do anything… its an automatic process…

Just one question:
Why do you want to install this driver? The notebook was preinstalled with the Windows system and all this drivers were already preinstalled…

Did you change the system in the past? What system do you use?

Hi

The driver installation order is important sometimes.
I would recommend installing the drivers in this order:
Windows 7
Windows Virtual PC KB958559
Windows XP Mode V.1.00_ENG
PlayReady PC Runtime 1.3
Intel Chipset SW Installation Utility 9.1.1.1020
Intel Management Engine Interface 6.0.0.1184
NVIDIA Display Driver 8.16.11.8829 (188.29)
Intel Turbo Boost Technology Driver 1.0.1.1002
Intel Rapid Storage Technology Driver v9.5.6.1001
TOSHIBA Supervisor Password Utility 4.2.1.0
TOSHIBA HW Setup Utility 4.2.1.0
TOSHIBA Value Added Package 1.2.34_64
O2 Card Reader Controller 2.0.24.D
NVIDIA HD Audio Driver 1.0.0.59
Conexant Audio Driver 4.98.16.61
Realtek Wireless LAN Driver 2.00.0006
Synaptics Touch Pad Driver 14.0.12.0
TOSHIBA HDD Protection 2.2.0.3
Bluetooth Stack for Windows by Toshiba v7.10.01(T)
Atheros LAN Driver 1.0.0.29
Winbond CIR Driver 8.60.2002
YUAN DVB-T/ATSC Tuner Driver 2.3.3.31
TOSHIBA USB Sleep and Charge Utility 1.3.2.0
TOSHIBA Face Recognition 3.1.3
TOSHIBA eco Utility 1.1.12.64
Sun Java2 Runtime Environment 1.6.0_14
TOSHIBA HDD/SSD Alert 3.1.64.4
TOSHIBA Service Station 2.1.40
HDMI Control Manager 2.0.0.3.64
TOSHIBA Remote Control Manager 3.0.1.0
TOSHIBA Fingerprint Utility V1.0.2.18
PatchFiles FixFPService_REG_1.0
ConfigFree 8.0.25
TOSHIBA Assist 3.00.10_O
TOSHIBA Web Camera Application V1.1.1.10
TOSHIBA Extended Tiles for Windows Mobility Center V1.01
TOSHIBA Network Device ID Registry Setting Tool 3.0.32.4-2
TOSHIBA Folder Migrating Utility 1.0.3.4