Solved Preview panel not functioning ONLY for MS Word .doc .docx .rtf files

[PivertMe]

Hello,

since a couple of weeks, without any voluntary modification of my system, .doc files can no more be previewed in preview panel.

I have MS Windows 7 Pro 64 bits
Paralle instal of Office XP and 2010 ( functionning normally, both "repair" installed to check if solves problem, but no change)

Pdf, jpg, rtf, txt are Ok

"advanced" text file formats not ( rtf / doc / docx)

Excel is ok; same for ppt files

I have repair installed Office XP, and Office 2010 : no change

Any help here to avoid reinstall Windows ? I have sadly forgotten to do system disk images for a while, and installed several programs since last system backup... Have been ill and less prudent when at the computer

Kaspersky Antivirus doesn't detect any virus

Chkdsk is OK
sfc reports no error

TIA !!

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Trying to update my display drivers I got a black screen. So had to reset. At reboot I chose to boot in safe mode and there preview was ok.
Restarted in normal mode, preview didn't work... So tried desactivate sole services and startup item, and rebooted. Again preview ok. So I will in the next days progressively re-activate some features with msconfig to narrow down to the faulty item. I will keep informed.
PS. Still using Windows 7 for all not web. Win 10 for web and some ohoto editing no more developed for 7 (but do not like 10). 11 is impossible with my hardware, and I cannot afford new computer. If MS drops me, I'll drop MS and switch to Linux. I cannot agree to that allways more. Money does not drop into my pockets.

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Finally Ashampoo Backup Pro is the program that causes this.
Desactivated at startup: OK
Activated at startup: no preview

Now uninstalled and OK

No idea as to the "why"