Thinking of using 
Zboot   by   ZBMsoft.com?
I wouldn't if I were you.  I've used it and as far as I'm concerned 
it might as well be a VIRUS!

I have 8 machines on an Ethernet at home.  They run from a PC XT (8086) to Pentium class XP ATs.  They all communicate on the same net.  I'm no newbie.  I wanted to observe the utility of WinXP compared to Win98 on my systems so I installed the virus, excuse me, I mean Zboot, on a number of my systems.  I did it one machine at a time, so I could evaluate my preference of OS prior to finally installing one or the other as the sole OS on that machine.  As far as I could tell from reading the README files, that was a legit use of the programs.

The version of the virus, excuse me, I mean Zboot, I installed, billed itself as a Demo copy which was hobbled.  Per the programmers description, it had generally the same features as a licensed copy but it would only allow booting to 2 different OS.  The fully functional licensed copy would allow booting to a larger number of OS.

The limited functionality was the only limitation of the virus, excuse me, I mean Zboot, that was mentioned in the description.  Ho, ho!!  Just wait about 20 days.  On boot up the program not only displays a message that you are using an unlicensed copy of the program, but it begins ratcheting up the delay before the machine boots.  After just 2 more boots there was a 5 minute delay.  It appears to increase an additional minute with each subsequent boot.  None of these consequences is mentioned anywhere in the notes as far as I could see.  I was even under the impression from the notes, that it was OK to use the demo as long as one wants.  It may have at least one other malicious effect which I think I have observed but I'm not sure of it so I'm not going to go into it.  I'm not about to leave the virus, excuse me, I mean Zboot,  on my machines any longer just so I can study this mischief.

If you want to encourage people to license your software, send them a message, send it every time the program starts, be annoying.  But don't be malicious.  Interfering with the functionality of the system is a NO NO!!
Use Zboot at your own risk!!