Some users are having a problem copy and pasting with Windows 7. The problem seems to be consistent with multiple applications. If you have a valid recent System Restore, Microsoft recommends this as a first course of action. If this does not work, use the System File Checker to check you system. Access SFC by:
1. Open an elevated command prompt. To do this, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
2. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
3. At the command prompt, type the following command, and then press ENTER:
sfc /scannow
For more information about using the system file checker, please refer to this Knowledge Base article: http://support.microsoft.com/kb/929833