Pb when installing "Windows installer 3.1"

I tried to install windows installer 3.1 through "Windows Update" and it didn't succeeded for many times.

I show and copy the beginning of KB893803.log :

[KB893803v2.log]
0.561: ================================================================================
0.561: 2006/04/22 00:32:57.021 (local)
0.561: c:\0939773b2060d7e984d4\UPDATE\update.exe (version 6.1.22.4)
0.581: Hotfix started with following command line:
3.025: In Function TestVolatileFlag, line 11660, RegOpenKeyEx failed with error 0x2
3.025: In Function TestVolatileFlag, line 11692, RegOpenKeyEx failed with error 0x2
3.025: DoInstallation: CleanPFR failed: 0x2

I downlowded MBSA in French and it tells me :

"le fichier catalogue est endommage ou introuvable" if I want analyse  the different security updates.

Is it a problem of "registre" (regedit) and I do not want format my hard disk.

Just to say that my Windows is a genuine.

Best regards

patrick