Is it possible to use remote desktop from Windows 7 to Ubuntu?

The protocol that Windows desktop sharing uses is called RDP. There is an RDP server implementation for Linux called xrdp but development has fallen behind and the RDP client in Windows 7 won't talk to the older version of RDP that it uses.

So if you want to connect to xrdp from Windows 7 you have to copy the old RDP client (mstsc.exe and mstscax.dll) from a WinXP install to the Windows 7 box and run it independently. At that point you might as well just be using a VNC client instead, really. VNC servers for Linux are much better-supported.

I believe you can use various VNC applications on Windows that are compatible with the built in one on Ubuntu. I really can not recommend any specific ones, as I have not used them since 2005. Remember to go to System -> Preferences -> Remote Desktop to set it up if Ubuntu is the guest.

I can attest that you can use vnc in windows 7 to connect to an ubuntu host just fine. I use the regular old VNC viewer. There really isn't a feature difference that I can see between doing this and using remote desktop.