How to Install a Microsoft voice on Windows 7 (tested on 32 bits e 64 bits)

(Leia em português)
These procedures must be performed by qualified technicians for Windows 7.
They were tested on Windows 7 32 bits and Windows 7 64 bits. (it may work for other systems, but I haven't test)
I recommend to do a system restore point before start the procedures below, in order to restore the system if something goes wrong.

Microsoft offers several languages for reading texts out loud voice for free.
As an example, I did the procedures using the Heloísa voice for reading texts in Portuguese (Brazil) and Hilda (espanish, Mexico), but it also works with several languages.
You will need to replace the line codes according to the voice that you'll install.
Ok, so let's start.

Step 1)
Install the Microsoft Speech Platform - Runtime (Version 11).
If your system is 32 bits, install the x86 version.
(x86_SpeechPlatformRuntime\SpeechPlatformRuntime.msi)

If your system is 64 bits, install the x64 version.
(x64_SpeechPlatformRuntime\SpeechPlatformRuntime.msi)

Download using this link:
http://www.microsoft.com/en-us/download/details.aspx?id=27225

Step 2) 
Install the language that you want in Microsoft Speech Platform - Runtime Languages (Version 11). 
Note: Download the TTS version.
My example:
(MSSpeech_TTS_pt-BR_Heloisa.msi)
 
Download using this link:
www.microsoft.com/en-us/download/details.aspx?id=27224

Step 3)  
Create a .reg file with the information according to your needs and then execute it as a system administrator. I will comment each line, then, I will show the complete file.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\Voices\Tokens\TTS_MS_lang-Country_Name_11.0]

My example:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\Voices\Tokens\TTS_MS_pt-BR_Heloisa_11.0]

Next line:

@="Microsoft Server Speech Text to Speech Voice (lang-Country, Name)"

My example:

@="Microsoft Server Speech Text to Speech Voice (pt-BR, Heloisa)"

To do the next line, you'll need this table:

410	Lucia	Microsoft Server Speech Text to Speech Voice (it-IT, Lucia)
413	Hanna	Microsoft Server Speech Text to Speech Voice (nl-NL, Hanna)
403	Herena	Microsoft Server Speech Text to Speech Voice (ca-ES, Herena)
41D	Hedvig	Microsoft Server Speech Text to Speech Voice (sv-SE, Hedvig)
80A	Hilda	Microsoft Server Speech Text to Speech Voice (es-MX, Hilda)
C0A	Helena	Microsoft Server Speech Text to Speech Voice (es-ES, Helena)
406	Helle	Microsoft Server Speech Text to Speech Voice (da-DK, Helle)
407	Hedda	Microsoft Server Speech Text to Speech Voice (de-DE, Hedda)
414	Hulda	Microsoft Server Speech Text to Speech Voice (nb-NO, Hulda)
40B	Heidi	Microsoft Server Speech Text to Speech Voice (fi-FI, Heidi)
C0C	Harmonie	Microsoft Server Speech Text to Speech Voice (fr-CA, Harmonie)
40C	Hortense	Microsoft Server Speech Text to Speech Voice (fr-FR, Hortense)
416	Heloisa	Microsoft Server Speech Text to Speech Voice (pt-BR, Heloisa)
816	Helia	Microsoft Server Speech Text to Speech Voice (pt-PT, Helia)
415	Paulina	Microsoft Server Speech Text to Speech Voice (pl-PL, Paulina)
419	Elena	Microsoft Server Speech Text to Speech Voice (ru-RU, Elena)
804	HuiHui	Microsoft Server Speech Text to Speech Voice (zh-CN, HuiHui)
404	HanHan	Microsoft Server Speech Text to Speech Voice (zh-TW, HanHan)
C04	HunYee	Microsoft Server Speech Text to Speech Voice (zh-HK, HunYee)
411	Haruka	Microsoft Server Speech Text to Speech Voice (ja-JP, Haruka)
409	Helen	Microsoft Server Speech Text to Speech Voice (en-US, Helen)
4009	Heera	Microsoft Server Speech Text to Speech Voice (en-IN, Heera)
C09	Hayley	Microsoft Server Speech Text to Speech Voice (en-AU, Hayley)
1009	Heather	Microsoft Server Speech Text to Speech Voice (en-CA, Heather)
809	Hazel	Microsoft Server Speech Text to Speech Voice (en-GB, Hazel)
412	Heami	Microsoft Server Speech Text to Speech Voice (ko-KR, Heami)

Replace "code" with the correspondent code of the language

"code"="Microsoft Server Speech Text to Speech Voice (lang-Country, Name)"

My example:

"416"="Microsoft Server Speech Text to Speech Voice (pt-BR, Heloisa)"

Next line:

"CLSID"="{a12bdfa1-c3a1-48ea-8e3f-27945e16cf7e}"

You will need to find the .dat file of the language. It will be in a folder similar to this, if your system is 32 bits:

C:\Program Files\Common Files\Microsoft Shared\Speech\Tokens\TTS_MS_lang-country_Name_11.0\MSTTSsomething.dat

or if your system is 64 bits:

C:\Program Files (x86)\Common Files\microsoft shared\Speech\Tokens\TTS_MS_lang-country_Name_11.0\MSTTSsomething.dat


According to that information, complete this next line, as my example:

"LangDataPath"="C:\\Program Files\\Common Files\\Microsoft Shared\\Speech\\Tokens\\TTS_MS_pt-BR_Heloisa_11.0\\MSTTSLocptBR.dat"

The next line, you need to replace the name + T. Examples: HildaT, HeloisaT, where Hilda is the mexican voice and Heloisa is the brazilian voice.

"VoicePath"="C:\\Program Files\\Common Files\\Microsoft Shared\\Speech\\Tokens\\TTS_MS_pt-BR_Heloisa_11.0\\HeloisaT"

In the next line, replace code with the same code that you used before:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\Voices\Tokens\TTS_MS_lang-Country_Name_11.0\Attributes]
@=""
"Age"="Adult"
"Gender"="Female"
"Language"="code"
"Name"="Microsoft Server Speech Text to Speech Voice (lang-Country, Name)"
"Vendor"="Microsoft"
"Version"="11.0"

My example:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\Voices\Tokens\TTS_MS_pt-BR_Heloisa_11.0\Attributes]
@=""
"Age"="Adult"
"Gender"="Female"
"Language"="416"
"Name"="Microsoft Server Speech Text to Speech Voice (pt-BR, Heloisa)"
"Vendor"="Microsoft"
"Version"="11.0"

Here an example of a complete .reg, in this case it will install TTS_MS_pt-BR_Heloisa_11.0 in a 32 bits system. Remember that you must execute the .reg as Administrator, otherwise, it will not work.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\Voices\Tokens\TTS_MS_pt-BR_Heloisa_11.0]
@="Microsoft Server Speech Text to Speech Voice (pt-BR, Heloisa)"
"416"="Microsoft Server Speech Text to Speech Voice (pt-BR, Heloisa)"
"CLSID"="{a12bdfa1-c3a1-48ea-8e3f-27945e16cf7e}"
"LangDataPath"="C:\\Program Files\\Common Files\\Microsoft Shared\\Speech\\Tokens\\TTS_MS_pt-BR_Heloisa_11.0\\MSTTSLocptBR.dat"
"VoicePath"="C:\\Program Files\\Common Files\\Microsoft Shared\\Speech\\Tokens\\TTS_MS_pt-BR_Heloisa_11.0\\HeloisaT"


[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\Voices\Tokens\TTS_MS_pt-BR_Heloisa_11.0\Attributes]
@=""
"Age"="Adult"
"Gender"="Female"
"Language"="416"
"Name"="Microsoft Server Speech Text to Speech Voice (pt-BR, Heloisa)"
"Vendor"="Microsoft"
"Version"="11.0"

Here another example installing TTS_MS_es-MX_Hilda_11.0 in a 64 bits system.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\Voices\Tokens\TTS_MS_es-MX_Hilda_11.0]
@="Microsoft Server Speech Text to Speech Voice (es-MX, Hilda)"
"80A"="Microsoft Server Speech Text to Speech Voice (es-MX, Hilda)"
"CLSID"="{a12bdfa1-c3a1-48ea-8e3f-27945e16cf7e}"
"LangDataPath"="C:\\Program Files (x86)\\Common Files\\Microsoft Shared\\Speech\\Tokens\\TTS_MS_es-MX_Hilda_11.0\\MSTTSLocesMX.dat"
"VoicePath"="C:\\Program Files (x86)\\Common Files\\Microsoft Shared\\Speech\\Tokens\\TTS_MS_es-MX_Hilda_11.0\\HildaT"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\Voices\Tokens\TTS_MS_es-MX_Hilda_11.0\Attributes]
@=""
"Age"="Adult"
"Gender"="Female"
"Language"="80A"
"Name"="Microsoft Server Speech Text to Speech Voice (es-MX, Hilda)"
"Vendor"="Microsoft"
"Version"="11.0"

Step 4)    Select the new installed voice by typing on Start menu change text to speech settings. Another way to access could be through Control Panel, Ease of Access, Speech Recognition, Text to speech. Select "Microsoft Server Speech Text to Speech Voice (pt-BR, Heloisa)". Test clicking on "Preview voice".

You can use "Narrator" that is pre-installed on Windows to test. On Narrator, change the voice at Voice Settings. If you have any question or suggestion, leave your comments bellow.

Sources:
http://answers.microsoft.com/pt-br/windows/forum/windows_vista-windows_install/microsoft-translator-fala-em-portugu%C3%AAs-como/04440df6-b5a5-4099-8dc6-6fd6b9b4f16a?msgId=28069a8c-0f7f-48df-950b-4cb84ea0aa18
http://www.microsoft.com/en-us/download/search.aspx?q=Microsoft%20Speech%20Platform%20-%20Server%20Runtime%20Languages&p=0&r=10&t=&s=availabledate~Descending
http://www.lomeutec.com/2012/02/narrator-faca-o-windows-7-falar-em.html
http://denspe.blog84.fc2.com/blog-entry-105.html
https://msdn.microsoft.com/en-us/library/hh378476%28v=office.14%29.aspx
http://siva.cc.hirosaki-u.ac.jp/usr/koyama/daisy/src/msharuka64.reg