I deleted my synaptics vertical scroll, how do i get it back

Multi-touch or multitouch functionality has been attracting consumer attraction, thanks to iPhone and iPod Touch, two-finger-scroll in Apple MacBook with TrackPad, and Windows 7, which has built-in multi-touch mapping application, photo viewing program, and gesture support in Internet Explorer 8. Multi-touch is essentially a set of interaction techniques which allow computerusers to interact and control graphical applications with fingers.
However, for marketing reason, Synaptics official standard drivers for most Synaptics TouchPads does not support multi-touch Synaptics Gestures. Synaptics' drivers lock gesture features on all non-supported OEM notebooks and laptop PCs, except for certain gadgets such as ASUS EEE PC. So multi-touch is disabled even though touchpad hardware does support them.
But now if you want to experiance this awesome multi touch features, well there is good news. One guy has developed a modded driver for synaptic which will enable the multi touch functionality in a normal PC with windows.
The Synaptics TouchPad driver should support all Windows operating system such as Windows XP, Windows Vista and Windows 7. However, do note that the digital signatures of the modded drivers have been broken, and the drivers are no longer signed. Thus, there may be issue when use in 64bit operating system which enforces strict driver signing requirements.
Installation:

1. Uninstall all current Synaptics drivers from Control Panel's Add and Remove Programs or Programs and Features.
2. Restart the computer.
3. Install the modded driver by running the setup.exe inside the ZIP archive.
4. Windows should prompt a warning about unsigned driver. Continue to install the driver anyway.
5. Restart the computer after installation is completed and Synaptics TouchPad driver is updated.
6. In Device Manager's Mouse and Other Pointing Devices" section, Synaptics PS/2 Port Touchpad should have driver version of 10.2.4.

Now just play around a little bit and you will know how awesome this features are.
Also there is a two finger scrolling application which is a project hosted in google code. So this application is all you need if you just need the 2 finger scrolling functionality in windows.
This application can be found here:
Download: http://code.google.com/p/two-finger-scroll/downloads/list
The moded drivers from synaptic can be found here:
Download synaptics_v10.2.4.0_allOS_modded_b2.zip or touchpad_synaptics_v10.2.4_vistax32x64_xpx32x64_modded_build2.zip
Or you can just download all the required files from here:
Mirrors:

1. Synaptics Multi touch mode (all) - Selfhosted
2. Synaptics Multi touch mode (all) - Rapidshare - Recommended

IMPORTANT: Do not upgrade the Synaptics TouchPad driver if you love these touch features, as Sypnatics locks and disable the advanced touch features from driver v11.0.0.0 onwards.