ExpressCache prevents disconnecting of portable USB disks

ch_djalel

Hi,

I am the owner of an Acer S3-391 with original OEM software (Windows 7 Premium Family Ed).

When I try to disconnect my portable USB hard disk (a 1TB Samsung S2) using the
icon in the tray, it fails and asks me to stop all programms that are still using this disk.

Actually, I stopped all running aplications and found that the only program that is still
accessing the portable USB disk is the ExpressCache service.

Before you ask, I've found it using procmon (Process Monitor) from sysinternals which can
be downloaded in the microsoft website. One needs to create a filter for disk path access
with the portable drive letter. procmon will then show that ExpressCache continues to access

the removable drive periodically.

I've found the command line that is suposed to prevent ExpressCache from
'caching/accessing' a certain drive. It is:

eccmd -excude <drive-letter>

Problem is, this command fails on my system with a strange error code. According to some support info
from the developpers of ExpressCache. This is normal, as they disable this  feature, in the OEM
version (sold to Acer and others). They also claim that ExpressCache only works on local disks

and should not touch removable drives. This is a false claim and I proved it using procmon, as explained earlier.

My question, is there a fix that we can get with an upgrade of ExpressCache software via Acer?

If not, is there a workaround other than stopping the ExpressCache service?

I've found some ExpressCache entries in the Windows registery.
One is:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\excfs
with the key DisplayName having the value ExpressCache File System Filter Driver

followed by a second called 'excsd'
with the key DisplayName having the value ExpressCache File Storage Filter Driver

Guess what? the second entry has an Enum sub-entry with:
- a key called Count having a value that is the exact number of disks in my system, including the removable USB drive.   
- other keys named 0, 1, 2, each with the name of one my disks. The last one is pointing to my removabe drive.

I guess one can force ExpressCache to forget about the removable drive by tweaking those registry entries.
But how? I don't one mess up my system. Not yet!

BTW, if there is really no program using the removable disk (other than ExpressCache) it can directly be unplugged

without disconnecting/ejecting it in Windows. ONLY if you didn't mess with Windows defaults for removable drives in the disk manager to delay write operations. That said, be warned I am not responsible for any damage or data loss that might occur if you this.