It actually is.

Unsolicited Remote Assistance does that, but requires destination user approval.

I understand you don't want to know much about Windows and VNC is most likely easier to get up and running, but just in case this helps:

On Source machine:
Start, Help and Support, Under "Pick a task" select tools, On the left menu: offer remote assistance, then type destinatio IP or hostname.

On destination machine: remote support must be enabled:
Right click on "my computer", properties, Remote, Allow users to connect remotely to this computer, Allow Remote Assistance Invitations to be sent to this computer.
also
Start, Run: "gpedit.msc", Computer COnfiguration, Administrative Templates, System, Remote Assistance, double click on "Offer Remote Assistance", Enabled, then, below, select "Allow helpers to remotely control", then click on "Show", add users you want to enable to control destination machine (DOMAN\Username or DOMAIN\groupname).

If you use Windows Firewall, you would also have to add the following exceptions to the Windows Firewall local or group policy.
Add the following entry to the Windows Firewall Port exceptions:
TCP port 135
The following entries to the Windows Firewall Program exceptions:
%WINDIR%\SYSTEM32\Sessmgr.exe
%WINDIR%\PCHealth\HelpCtr\Binaries\Helpsvc.exe
%WINDIR%\PCHealth\HelpCtr\Binaries\Helpctr.exe

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Otherwise, I find Ultr@vnc (ultravnc.sourceforge.net) the best incarnation of VNC in Widnows even though I don't think I tested all those around. It does perform poorly as compared to the above in terms of speed. Still good, though, and free as well.