Could not use file already in use

[pheas82]

Hi;
My site is giving this error sometimes:

Could not use ''; file already in use

When i refresh page,site is opening.I inspected internet.And i found that this is about database permissions.

My site is using PLESK 7.5.4.And when i enter database permissions;I am seenig these:

1-Administrators (i can't change this)
2-Plesk Domain User (my_site's_name) (i can't change this)
3-SYSTEM (i can't change this)
4-FrontPage Server Extensions Anonymous Group (FPSE_15245)
5-Plesk IIS User (IUSR_my_site's_name)
6-Plesk IIS WP User (IWPD_48(my_site's_name))

That's permissions:
READ WRITE EXECUTE
1- X X X
2- X X X
3- X X X
4- ? ? ?
5- ? ? ?
6- ? ? ?


What must i do 4.,5. and 6.'s permissions?
THANKS............

 

[jbuts]

Actually, you should add "write and modify" permission for "Plesk IIS User (IUSR_my_site's_name)" user

 

[pheas82]

It is giving same error.I used all variations of permissions.But same error.Please help me