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#1
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Protecting Spreadsheet
Hi all,
I have developed a spreadsheet that I am planning on selling. I am offering a free trial of my spreadsheet, and after 30 days, it lock the user out. This does not stop the user from downloading another version. Is there anything in excel or some coding that will remember if someone has downloaded the trial version before? Any help would be much appreciated. Thanks Jason |
#2
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Protecting Spreadsheet
Nothing that cannot be circumvented. Also, how do you plan on "locking the
user out?" -- Vasant "Ashman" wrote in message ... Hi all, I have developed a spreadsheet that I am planning on selling. I am offering a free trial of my spreadsheet, and after 30 days, it lock the user out. This does not stop the user from downloading another version. Is there anything in excel or some coding that will remember if someone has downloaded the trial version before? Any help would be much appreciated. Thanks Jason |
#3
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Protecting Spreadsheet
You might be able to put something into the windows registry and check it when
you open the workbook. But if you can put it there, then anyone can clean it up. So it's not foolproof. Look in VBA's help for GetSetting and SaveSetting for examples. But this would also depend on having your project protected--and that protection can be bypassed pretty quickly. Ashman wrote: Hi all, I have developed a spreadsheet that I am planning on selling. I am offering a free trial of my spreadsheet, and after 30 days, it lock the user out. This does not stop the user from downloading another version. Is there anything in excel or some coding that will remember if someone has downloaded the trial version before? Any help would be much appreciated. Thanks Jason -- Dave Peterson |
#4
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Protecting Spreadsheet
Good evening Jason You could use the SaveSetting and the GetSetting instructions to writ a key to the registry - this could be used to highlight whether a P has used this particular software before. Be aware, however that Exce applications can be "broken", VBA project passwords can be remove fairly easily by those in the know - and if someone knows how to remov a VBA password, they'll know enough about VBA to trace what you've don and remove it. HTH Dominic -- dominic ----------------------------------------------------------------------- dominicb's Profile: http://www.excelforum.com/member.php...fo&userid=1893 View this thread: http://www.excelforum.com/showthread.php?threadid=37755 |
#5
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Protecting Spreadsheet
I am more optimistic that controlling the distribution / the integrity of
the code would be more a business software developers concern, than people not paying the licensing fee. And even where we've come to expect no honor in the population at large - downloaded music - I just read tonight that iTunes downloads has eclipsed P2P music downloads. http://news.yahoo.com/news?tmpl=stor...08/bs_nf/36124 Would any of the developers in this forum care to share their thoughts for naive souls like myself to learn from? Thanks... "Dave Peterson" wrote in message ... You might be able to put something into the windows registry and check it when you open the workbook. But if you can put it there, then anyone can clean it up. So it's not foolproof. Look in VBA's help for GetSetting and SaveSetting for examples. But this would also depend on having your project protected--and that protection can be bypassed pretty quickly. Ashman wrote: Hi all, I have developed a spreadsheet that I am planning on selling. I am offering a free trial of my spreadsheet, and after 30 days, it lock the user out. This does not stop the user from downloading another version. Is there anything in excel or some coding that will remember if someone has downloaded the trial version before? Any help would be much appreciated. Thanks Jason -- Dave Peterson |
#6
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Protecting Spreadsheet
I'm not a developer, but have been around Excel NGs for many years. And I
can tell you that most "real" Excel developers rely primarily on the honor of the general public. There is no good way to protect any Excel-based program from unethical users. You have to deem it a cost of doing business. Additionally, I find that those who post questions about "protecting" their programs have a highly inflated view of the value of the same. Just my $0.02. -- Vasant "William Benson" wrote in message ... I am more optimistic that controlling the distribution / the integrity of the code would be more a business software developers concern, than people not paying the licensing fee. And even where we've come to expect no honor in the population at large - downloaded music - I just read tonight that iTunes downloads has eclipsed P2P music downloads. http://news.yahoo.com/news?tmpl=stor...08/bs_nf/36124 Would any of the developers in this forum care to share their thoughts for naive souls like myself to learn from? Thanks... "Dave Peterson" wrote in message ... You might be able to put something into the windows registry and check it when you open the workbook. But if you can put it there, then anyone can clean it up. So it's not foolproof. Look in VBA's help for GetSetting and SaveSetting for examples. But this would also depend on having your project protected--and that protection can be bypassed pretty quickly. Ashman wrote: Hi all, I have developed a spreadsheet that I am planning on selling. I am offering a free trial of my spreadsheet, and after 30 days, it lock the user out. This does not stop the user from downloading another version. Is there anything in excel or some coding that will remember if someone has downloaded the trial version before? Any help would be much appreciated. Thanks Jason -- Dave Peterson |
#7
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Protecting Spreadsheet
If you mean just a simple spreadsheet - with no code - then there's nothing
you can do. Any VBA code can be hacked in minutes - just google "excel password protection" for tools to do this. The safer way to do this is write the code as VB and compile into a COM add-in for excel. Then have this look at the registry for a hidden value. But, it's trivial to see what is being written and read from the registry (regspy is one such tool) so you cannot really do this. For what it's worth, I think you are better off compiling the code with a drop dead date. Then the "bad" user will have to change their system clock to get the code to work. Generally, this does not work too well, except in the case where the user supplies parameters that you compile into the code, but that's very very messy. -- www.alignment-systems.com "Ashman" wrote: Hi all, I have developed a spreadsheet that I am planning on selling. I am offering a free trial of my spreadsheet, and after 30 days, it lock the user out. This does not stop the user from downloading another version. Is there anything in excel or some coding that will remember if someone has downloaded the trial version before? Any help would be much appreciated. Thanks Jason |
#8
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Protecting Spreadsheet
I agree with Vasant.
Protection will keep the non-curious honest users out. But even the honest curious may be overwhelmed by the challenge <bg. William Benson wrote: I am more optimistic that controlling the distribution / the integrity of the code would be more a business software developers concern, than people not paying the licensing fee. And even where we've come to expect no honor in the population at large - downloaded music - I just read tonight that iTunes downloads has eclipsed P2P music downloads. http://news.yahoo.com/news?tmpl=stor...08/bs_nf/36124 Would any of the developers in this forum care to share their thoughts for naive souls like myself to learn from? Thanks... "Dave Peterson" wrote in message ... You might be able to put something into the windows registry and check it when you open the workbook. But if you can put it there, then anyone can clean it up. So it's not foolproof. Look in VBA's help for GetSetting and SaveSetting for examples. But this would also depend on having your project protected--and that protection can be bypassed pretty quickly. Ashman wrote: Hi all, I have developed a spreadsheet that I am planning on selling. I am offering a free trial of my spreadsheet, and after 30 days, it lock the user out. This does not stop the user from downloading another version. Is there anything in excel or some coding that will remember if someone has downloaded the trial version before? Any help would be much appreciated. Thanks Jason -- Dave Peterson -- Dave Peterson |
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