Site causes pc lag (up to minute)

Hi,
on of my users has reinstalled system few days back – Fresh W7 x64 and latest version of google chrome and when he tries to load my web page his pc totally freezes (even no mouse respond). Few other users reported the same issue (like even months back), but I could not get any specific info from them…. :-/
I was wondering if anyone had the same problem or if there is some known issue (like certain plugin).
I will try to collect more specific info from these users and add any info that might help soon -Iam really busy these days.
Thanks a lot!