I can confirm this behaviour, but it is (usually) not a problem and has a pretty normal reason.
Does this also happen with other software and files from the HDD/network?
Did it happen before, like it was always this way, or just recently? If so, what did you change?
Will the 100% CPU usage remain or sink after the file is completely loaded?
"After (opening) 5-6 documents" means opened "all at once" or "subsequent"? If all at once, how much RAM do you have and is there enough space left on the HDD for cache?
Is preflight activated?
Do the documents have broken cross-refs to other documents?
What means "hanging"? Hanging like "for a while" or like "forever"?
Sorry my misstake.
InDesign will hang while open file permanent and can't open file really. i was waiting more then 30 minutes and nothing happen (CPU everytime 100%)
with after 5-6 documents i mean they was open normal.
Yes, but still, 5-6 documents with one open each time or all 6 open at once? If latter, then it could have run out of memory.
Particularly if the user never does a Save As to remove useless change information in files that have been edited many times.