our w7 clients cannot install applications. is there a way to configure their registry to allow them to install adobe flash player?

Most likely Applocker is configured. What you should do is make an exception for Adobe Flash Player so it can be installed. Here is more information about Applocker: Windows 7 AppLocker Executive Overview Here is an example of how you can create a Publisher rule to allow the installation of Adobe products, using a local security policy: To create a new rule with a publisher condition by using the Local Security Policy snap-in Click Start, type secpol.msc in the Search programs and files box, and then press ENTER. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Yes. In the console tree, double-click Application Control Policies, double-click AppLocker, and then click the rule collection that you want to create the rule for. On the Action menu, click Create New Rule. On the Before You Begin page, click Next. On the Permissions page, select the action (allow or deny) and the user or group that the rule should apply to, and then click Next. On the Conditions page, select the Publisher rule condition, and then click Next. On the Publisher page, click Browse to select a signed file, and then use the slider to specify the scope of the rule. To use custom values in any of the fields or to specify a specific file version, select the Use custom values check box. For example, you can use the asterisk (*) wildcard character within a publisher rule to specify that any value should be matched. Click Next. (Optional) On the Exceptions page, specify conditions by which to exclude files from being affected by the rule. Click Next. On the Name and Description page, either accept the automatically generated rule name or type a new rule name, and then click Create. Source: http://technet.microsoft.com/en-us/library/ee791783(v=ws.10).aspx