client had a problem with glacial logons, slow network share enumeration, and Outlook synchronization failures. Outlook 2010 took up to ten minutes to shutdown connections to Exchange.

The first changes (autotuning and rss) solved the issue for this site but it’s good to have additional steps to try.

Try these items

From an administrator command prompt:

netsh interface tcp show global

- Write down the setting so that you can go back to the way it was.

Netsh interface tcp set global autotuning=disabled
Netsh interface tcp set global rss=disabled

-Reboot
-Test

- If this didn't work; put it back

Netsh interface tcp set global autotuning=normal
Netsh interface tcp set global rss=enabled

- Reboot
- Test

-Next thing to try

netsh int ip show offload
netsh int ip set global taskoffload=disabled

- Reboot
- Test

- If this didn't work; put it back

netsh int ip set global taskoffload=enabled

- Reboot
- Test

-If any of the above improve performance; keep and move to the next.

-Next thing to try

Also you may try disabling the power management option on the NIC as follows:

1. Click Start, right click Computer select Properties.
2. Click Device Manager. Right-click your NIC and choose Properties.
3. Choose Power Management tab and uncheck Allow the computer to turn off this device to save power.
4. Restart the computer and check if it works.

This should help especially with the Network disconnects.

Other things to try

http://support.microsoft.com/kb/829700

Changing the registry

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:  322756 (http://support.microsoft.com/kb/322756/ ) How to back up and restore the registry in Windows

1. Add the SuppressionPolicy DWORD value to the following registry key:

HKEY_CLASSES_ROOT\*\Shellex\PropertySheetHandlers\CryptoSignMenu

 To do so:
 
 1. Click Start, and then click Run.
 2. In the Open box, type regedit, and then click OK.
 3. Locate and then click the following registry key:

 HKEY_CLASSES_ROOT\*\Shellex\PropertySheetHandlers\CryptoSignMenu

 4. On the Edit menu, point to New, and then click DWORD Value.
 5. Type SuppressionPolicy, and then press ENTER.
 6. On the Edit menu, click Modify.
 7. Click Hexadecimal, type 100000 in the Value data box, and then click OK.

2. Add the SuppressionPolicy DWORD value to the following registry key:

HKEY_CLASSES_ROOT\*\Shellex\PropertySheetHandlers\{3EA48300-8CF6-101B-84FB-666CCB9BCD32}

 To do so:

 1. In Registry Editor, locate and then click the following registry key:

 HKEY_CLASSES_ROOT\*\Shellex\PropertySheetHandlers\{3EA48300-8CF6-101B-84FB-666CCB9BCD32}

 2. On the Edit menu, point to New, and then click DWORD Value.
 3. Type SuppressionPolicy, and then press ENTER.
 4. On the Edit menu, click Modify.
 5. Click Hexadecimal, type 100000 in the Value data box, and then click OK.

3. Add the SuppressionPolicy DWORD value to the following registry key:

HKEY_CLASSES_ROOT\*\Shellex\PropertySheetHandlers\{883373C3-BF89-11D1-BE35-080036B11A03}

 To do so:

 1. In Registry Editor, locate and then click the following registry key:
 
 HKEY_CLASSES_ROOT\*\Shellex\PropertySheetHandlers\{883373C3-BF89-11D1-BE35-080036B11A03}

 2. On the Edit menu, point to New, and then click DWORD Value.
 3. Type SuppressionPolicy, and then press ENTER.
 4. On the Edit menu, click Modify.
 5. Click Hexadecimal, type 100000 in the Value data box, and then click OK.

4. Add the Flags DWORD value to the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\SCAPI

 To do so:

 1. In Registry Editor, locate and then click the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\SCAPI

 2. On the Edit menu, point to New, and then click DWORD Value.
 3. Type Flags, and then press ENTER.
 4. On the Edit menu, click Modify.
 5. Click Hexadecimal, type 00100c02 in the Value data box, and then click OK.
 6. Quit Registry Editor.