How to repair a corrupt Windows 7 installation

Symptoms

Cannot install Parallels Tools.

Virtual hardware drivers provided by Parallels Tools do not work properly.

System File Checker tool is unable to repair corrupt system files and shows that the system has integrity violation.

Cause

System corruption.

Resolution

This article applies to Windows Vista and Windows 7 only. If you have Windows 8 virtual machine, please check this article.

Please take a snapshot of your virtual machine (in Parallels Desktop menu bar go to Virtual Machine (Actions for Parallels Desktop 10) > Take snapshot... before you proceed with instructions below to be able to revert all the changes.

Note: it is not possible to take the Snapshot of Boot Camp virtual machine.

1. Start Windows virtual machine normally.

2. Insert the Windows installation disk (or use the .iso image located on the computer):

   2.1 In virtual machine Configuration go to Hardware > CD/DVD 1.

   2.2 Make sure that Connected box is checked.

   2.3 Specify the disk/image location in Connect to: box.

3. Start Windows Explorer, open installation disk and launch setup.exe file.

4. On the Install Windows page, click Install Now.

5. On the Get important updates for installation page, we recommend getting the latest updates to help ensure a successful installation and to help protect your computer against security threats. You need an Internet connection to get installation updates.

6. On the Please read the license terms page, if you accept the license terms, click I accept the license terms, and then click Next.

7. On the Which type of installation do you want? page, click Upgrade to begin the upgrade.

You might see a compatibility report.

• If the compatibility report fails with error that there is no enough space, please shut down virtual machine and increase virtual hard drive space: in Parallels Desktop menu bar: Virtual Machine (Actions) -> Configure -> Hard Disk 1 -> Edit (Windows needs 20 GB of free space to be upgraded).

NOTE: we strongly recommend you to take a backup copy before resizing. Please copy your virtual machine .pvm file (its default location is Users/username/Documents/Parallels) in another directory on your Mac or external drive.

• If the compatibility report fails with compatibility error (your current system build is newer than which is on CD/DVD/image), then you will have to uninstall Service Pack 1 before performing an upgrade install:

https://windows.microsoft.com/en-us/windows7/uninstall-sp1

• Repeat 1-7 steps and install Parallels Tools after Windows 7 Upgrade.

To delete the Snapshot in Parallels Desktop menu bar go to Virtual Machine (Actions) > Manage Snapshots....

NOTE: if you use Boot Camp virtual machine, then boot Windows from Boot Camp partition, skip Step 2 and just insert the Windows installation disk.

Also, Parallels Desktop does not provide tools to resize Boot Camp partition.

If Windows does not boot, please refer to Windows 7 Recovery Tools.