I disabled the AV only to get them down, 7-zip was ok with them, used last beta, and so I got it!
Can you clarify: what did you do?
Did you run 7-zip beta and opened the floppy archiv XP_INST.IMA?
Did you extracted any file?
Did you run any extracted application?
But I powered off the system in the middle of something (there were already some weird things going on) and on power on it became evident that there is a problem, even the simplest thing, like double clicking "My Documents" or "My Computer", didn't work as expected, due probably to registry inconsistencies - did I tell you I powered off the system in the middle of something?
Well, this may be a file system corruption or registry corruption.
There may a malvare involved or not. a malvare may be active already, before downloading XP_INST_v04.7z.
Hardware failure is another possible cause.
I could have submitted the archives to AV sites, but another part of the problem is that this kind of sites can be used for malware optimization too - bad guys just submit themselves their "work" until they get "AV clearance", so to speak.
What do you suggest instead now?