How to reverse an accounts receivable entry in Quickbooks Pro2007

Did you do any backups?

Check your paperwork. You should have received this information when you purchased Quickbooks.

http://support.quickbooks.intuit.com/support/Articles/SLN53503

Open the apply payments window and choose the customers name at the top. Click next to the invoice that you want to pay and then at the bottom of the screen look for the button that says discounts and credits. Click on it and then choose credits. The credit should be listed there to apply to the invoice. If you have tried these steps

Are you receiving $ by:
a) entering "Sales Receipts" (or)
b) entering "Invoices"

You may want to request the FREE
"3 Step Picture Guide" for getting started with QuickBooks - available at:
http://www.accountingdirectors.com/training.aspx

It's likely a problem with the PDF Converter provided by Intuit. Here are the instructions to fix the problem:

http://support.quickbooks.intuit.com/support/pages/knowledgebasearticle/1007856

If that does not fix your problem, take a look at turning User Account Controls either ON or OFF -

1. From the Windows Start menu, choose Control Panel.
2. Double-click User Accounts, and then click Turn User Account Control on or off. Click Continue if asked for permission to continue.
3. Select the checkbox Use User Account Control (UAC) to help protect your computer and click OK. Close Control Panel.
4. Restart your computer

Please let me know if this has been helpful or if there is anything else I can do. Thank you.

look for a button that says undo changes....

Trying going to this link:

http://quickbooks.intuit.com/downloads/2007/pro.jsp

You will need to have your numbers ready. And it may take a while.