If you have to reinstall or you have cancelled your account, you will want to uninstall the Method Sync Engine.

1. Shutdown the Method Sync Engine

Open QuickBooks.
Bring up the Method Integration Sync Engine (right-click the Method:CRM icon in your taskbar and click Display).

If the Method Integration Engine is not running, click Start > Programs > Method > Method Integration Engine for Use with QuickBooks.
In the Method Integration Engine, click Disconnect.
Click Synchronize > Real time QuickBooks Subscription > Remove Subscription.
Click File > Shut Down.

2. Remove Permissions from QuickBooks Desktop

In QuickBooks Desktop, click Edit > Preferences.
Click Integrated Applications > Company Preferences > Method Integration Engine Listener > Remove > Yes.
Click Method QuickBooks Desktop Integration Engine for use with QuickBooks > Remove > Yes > OK.
Close QuickBooks Desktop by clicking File > Exit.

Once QuickBooks is closed, try to reopen it.

If you receive the message to enable Method with QuickBooks again, click Cancel and continue with 3a. Uninstall Method Integration Engine Via Tool below.
If you do not receive a prompt from QuickBooks asking for Method:CRM to connect, move to 3b. Uninstall Method Integration Engine Manually.

QuickBooks Desktop must be closed.
Open My Computer and navigate to:
C:\Documents and Settings\AllUsers\Application Data\Intuit\QuickBooks
(If you are unable to locate this directory, use the Find tool on your computer to search for the file called “qbsubconfig.xml".)
Delete the file called qbsubconfig.xml.
Reopen QuickBooks Desktop.
In Windows, click Start > Control Panel > Add or Remove Programs.
Remove the Method Integration Engine.
Remove the Method Integration Listener.

If you are removing the engine to reinstall Method:CRM, proceed to our QuickBooks Desktop Install article.