[HTC Desire S] Forwox:
YESSSS, FINALLY DID IT!!! :D

What were my problems? RUU was the incorrect versions, few problems with PC drivers, that's why fastboot recovery flashing didn't worked and the only way to go was Revolutionary, but it does not work on 2.00.xxxx HBOOT version, that's why downgrade was needed.

My HTC Desire S now:

Before:

What have I done:

*HTCDev.com Unlock and then Relock, downgrade from HBOOT-2.00.0002 to HBOOT- 0.98.0002 is done, RUU installed, S-OFF made via revolutionary, MIUI ROM installed.*

Here is a little walkthrough from *pain in the ass* to total success how it was in my case :):

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1. Installed all necessary android related drivers to PC.

2. In Desire S phone turned off "fastboot" option in Settings/power/fastboot. Turned on USB debugging Settings/Applications/Development/USB debugging

3. Switched on and connected phone to PC (Charge only).

3.1 If your HTC Desire S in HBOOT shows pink ***LOCKED*** go to HTCDev.com and unlock it.

4. Downloaded files from this topic: http://xdaforums.com/showthread.php?t=1399331 (zergRush and misc_version ONLY!!!)

Unziped the downloaded files in a folder (e.g. c:/Users/yourName/Downloads)

5. In Windows went to Start>Run and typed cmd. Now you needed to relock the bootloader with the, so typeed command "fastboot oem lock" in terminal just just I opened. "I recommend to restart the phone and after that connect to Charge only again as before."

3. Run the Terminal again and changed into the folder where I unzipped files before (change folder with 'cd')

4. Now typed to the terminal (every line is one command!)

adb push zergRush /data/local/tmp

adb push misc_version /data/local/tmp

adb shell chmod 777 /data/local/tmp/zergRush

adb shell chmod 777 /data/local/tmp/misc_version

adb shell

(IF THERE IS ANY PROBLEM WITH zergRush or BOOMSH, and only $ shows up, type this):

4.1 rm /data/local/tmp/boomsh

4.2 rm /data/local/tmp/sh

4.3 cd /data/local/tmp/

IF NO PROBLEM EXPLAINED ABOVE, THEN KEEP TYPING AFTER PREVIOUS adb shell THIS:

cd /data/local/tmp/

./zergRush

5. Then typed

adb shell /data/local/tmp/misc_version -s 1.27.405.6

"This will change your version information, but you need the same RUU version!"(don't type this in cmd, of course)

6. Now found appropriate RUU for device. I used RUU_Saga_HTC_Europe_1.47.401.4_Radio_20.28I.30.085AU_3805.06.02.03_M_release_199410_signed and it worked like a charm!!! I have tried two other with no success on downgrade. My Desire S is non-branded!

7. Run that downloaded RUU .exe file, went to Start>Run and typed in %temp% Now clicked "Date modified" and found the newest folder and in there will be file called rom.zip. Copied this file to the desktop and renamed it to PG88IMG (adding .zip extension was the trouble maker for me! But you can try)

8. Copied this file to my SD card and start the phone in HBOOT (turn it on whilst holding volume down). The phone found the file and started the update.

9. Phone restarted and you I saw HBOOT- 0.98.0002 instead of HBOOT-2.00.0002 as it was before. If it is like that, then you have successfully downgraded your HTC Desire!

8. Now just download revolutionary from http://revolutionary.io and create a beta key and start programm. It will do S-OFF on your device.

DONE!

Now you can install any ROM by your choice.

Good luck and don't give up! It took me 3 days, but I didn't gave up. :)

I hope this report somehow helps users like me, who faces the same problems and storyline. ;)

Many thanks to foX2delta and SuperKid who helped, and topics in this forum. :)