If you type "link" you will see what TCP options your OS currently uses.
The following 3 options can be enabled:
On windows systems, wscale & timestamps are disabled by default,
that's not optimal. I'm pretty sure there are some small freeware
tools you can download that will set all these for you, but here is a
link I found if you want to enable these options manually:
Cutting & pasting:
The Tcp1323Opts value in the following registry key can be added to
control scaling windows and timestamp:
1. On the toolbar click Start, click Run, and then type Regedit to
start the Registry Editor.
2. In the Registry Editor, click Edit, point to New, and then click
3. In the New Value box, type Tcp1323Opts, press ENTER, and then on
the Edit menu, click Modify. Note The valid range is 0,1,2 or 3 where:
0 (disable RFC 1323 options)
1 (window scale enabled only)
2 (timestamps enabled only)
3 (both options enabled) ### THIS is what you want!