Can't create new section from another computer

[mmarch]

Hi!!!

I host my site on my home compuer. When i try create new content from home computer everything work fine. If i do that from job computer i receive error message -

Line:    2
Char:   76196
Error:   Access is denied
Code:   0
URL:     http://mydomain/administrator/index2.php

I run winxp pro, XAMPP webserver and configured my server for virtual hosting also (i have another full working website on my machine). How i gather from another posts, my installation process was just litle different, like if i use 3d party hosting services. I just unzip installation files directly in my site folder. How i understood In another instances peoples should upload their site by ftp with permision XXX. Due security reasons i made site folder just READ ONLY (by folder properties ticking this section, and apply for ALL content in this folder). When i tryed create new section from my job computer i receive this error message.
After this i try create new section from home computer and all work fine. Today morning i untick READ ONLY box in folder properties and tryed again create new section from job computer. And again receive this error message.
How i can fix this problem?

[CREATIVE Options]

Please try to login with the invaluable "www"

http://www.mydomain/administrator/index2.php

[mmarch]

OK, Thank's for replay, i will try monday. And let you know.