UnZipMBS very slow in Windows?

My app bundles a lot of support files and unpacks them on first run.
On the Mac and my Windows machines, the unpacking takes maybe 5 seconds.

Im hearing from some Windows users where the process is taking an hour or more.
Has anyone seen similar, and any advice other than ‘maybe its a virus checker’ (probably Avast again…)

We use MBS to unzip fairly large files on Mac/Windows and it seems quite fast on most systems. I think you may be on the right track with the anti-virus thing–is very possibly anti-virus software slowing things down as the files are unzipped.

maybe you measure what takes so long?

On my machine, its fast.
On some users machines, it is slow.
By the time we find out who was slow, the problem is over and the files are installed.
At the moment, Im just wondering if anyone else is seeing the same thing, before I consider adding rarely used debugging code.

Well, if some other tool intercepts creation/writing of files to check for what the file content is, it may slow down.