Adb Drivers: rk28usb-new

The adb drivers for Windows XP should also be inside the pack, but I do not have a device to find out myself.
Flash tool is in RKAndroidTool

The RKAmdroidTool may not work until you modify the settings.ini to match VID and PID of your A7HT.
Refer to my translated .ini file for help with flashing in this post: http://slatedroid.com/index.php?topic=3 ... 36#msg3336
You need to save this as English.ini beside Chinese.ini under the Language folder, then change the display language in setting.ini
There's also instructions on slatedroid in the download section. I know Chinese so I can translate more of the manual too if you want.
The offsets for your device might be different than that of the SDK toolkit as well. So be aware of that.
Making your own update.img
You need to have the appropriate files under /rockdev/Image
Then just run mkupdate.bat and update.img will be generated.
About .img files located under rockdev/image
These contain data to be flashed to your device.
The .img files are cramfs and can be unpacked in Linux, modified and repacked. The toolkit should give you everything you need to create your own ROMs.
There are some .img files located in this SDK kit probably are not compatible with your Archos 7 HT, as they are intended for this so called MD01 device, which is probably a SDK device that the Apad is identical to.
Root ideas
To get root, you likely need to somehow modify your default.prop to say:
ro.secure=0
Just unpack your update.img using AFPTool, creating a folder 'updatefolder' first:
AFPTool.exe -unpack update.img updatefolder
Now go modify boot.img.
To make an update.img, use mkbootimg.bat and modify the bat file so it points to your modified folderpath.
You will now have a pre-rooted update.img pack.
Hopefully adb is enabled already. Anyways then you need the su binaries to be pushed to bin and xbin, chmodded. Finally push a Cupcake compatible Superuser.apk. You can also find that on slatedroid.
Warnings
I do not have an Android tablet myself, as an owner of a HTC Dream G1 who has been frequenting xda developers.