Auto Reminder mail from Excel when the PC is powered on or signed in

Dear Friends,
I don't know anything about VBA or Macros. But I want the excel to send a reminder e mail 30 days prior to the expiry of an item from a list of items (Column 1). I have googled and found this VBA code. It works fine, but only if I select RUN on the VBA page. I am not sure whether I have done the complete procedure to set it up. I only pasted the code from internet to the Excel VBA page. I opened the VBA page by right clicking the sheet1 tab and selecting view code. To test it I added few more items with expiry date within 30 days and removed all “Y” from column 12. But only the existing items mail was send after selecting “run” from Vb page, not the newly added ones.
I would like the excel to send e mail to the email address (Column 9) automatically whenever the expiry date (Column 4) is 30 days away and whenever the PC is powered on. Or when the PC is signed in. The PC is always on. I shall upload the file created. Kindly help me to fix it.
Thanks & Best regards
Prakash

Dear Blokeman and friends
this is the first i ever joined a forum. I first joined chandoo.org and posted my query. The forum said there will be a response in 24hrs. Since no response for 3 days, i thought i might have made some mistakes in posting and might have dumped. Hence i posted in Excel forum. I didn't know there is something called cross posting until now. If i have hurt the sentiments and good intentions of good Samaritans of both the forums, please accept my apologies.
Best regards Prakash

Sorry Mr. Blokeman
i di not understand "Paste the code in "ThisWorkbook".
thanks Pramal11

Thank You Sir,
I have read this before and I have pasted the code as it says in the sheet 1.
Sorry but Kindly advice what went wrong and advice how to correct it. I am novice to Excel, VBA and Marcos. I shall list down what the issues with the attached Excel file (MAA SHELF LIFE).
1) The code works fine when I select "run" on the VBA page menu bar. It will send a outlook mail to the emil ID in col 9 for any items expiry date is 30 days or lesser away.
2) But if i add any more items below the existing items with an expiry date 30 days or less, it will not send mail even when i select "run".
3) I have pasted the code by right clicking the SHEET 1 tab and selecting "view code". I didnt do anything else. did not create a module or name the project. Just pasted the code.
4) I have edited the code to change the column number to suite my Excel sheet. I guess the code runs fine if I select "run", may be the code is ok.

What I would wish to have:
1) If possible the code should run on anybody signing in the PC ( PC is almost allways Power On but signed out) and check the expiry date list (Col 4)and if there is any dates less than 30 days and if there is no "Y" in column 12, send a email reminder to email ID in Col9. Without opening the work book.
2) In another thread says we can schedule the opening of the workbook daily by scheduler. Not sure how to set up that.

Thanking You in advance for all your help.
Best regards Pramal11

Many Many thanks Sir
I shall do as advised. Could you kindly advice how to set up scheduler to automatically open the work book and run the marco every day witjout any humans intervention. PC is always on but signed out.
Thanks again
pramal11

Dear Sir,
As advised I have pasted the code in workbook and it run when ever I open the workbook.
Would it be possible to set it to run on signing in to the PC.
Also, What is ment by "For i = 6 To Range("C65536").End(xlUp).Row"
especially ("C65536"). What is this number specify.
Many Thanks for your help
Pramal11

Dear Sir,
Thanks a TON for your help. I managed to set up the scheduler to open the work book at sign in.
If you dont mind, Kindly advice what is the number ("C65536") in this part of the code specify "For i = 6 To Range("C65536").End(xlUp).Row".
Is there any way we could run the code without opening the work book physically. That is open - run the code - close without anyone seeing it.
Thanks Nd Best Regards Prakash

Many many thanks Sir for all your help.

Dear Sir,
Sorry to bother you again.
Everything works fine....Thanks to you.
But after I copy it on a thumb drive and paste it on to another PCs desktop, its opening only in "READ ONLY" mode. I havent protected it. Then I selected "Shear Workbook" saved it and repeted the copying on thumb drive and pasting on new PC. Now its working on the new PC. But I canot see the code in the workbook. But it works fine. Since the work book is in shear mode, I canot protect it or hide the rows containing formulas. Is there any way I could protect the row with formulas, to prevent accidental deletion.
Thanks in advance for your help.
Best Regards Pramal11

Dear Blokeman,
Would it be possible for the code to check one more column. If the date in that column 6 is todays date minus 2days, it should send a mail to the maild ID in coulmn 10, with the same subject and body as in the existing code. Also repeat the reminder mail on todays date.
Grateful if you could help.
My previous mail with file shear issue is still not fixed. I couldnt find a way to fix it.
Thanks Nd Brgds Pramal11.