Windows Vista system disk space solution

Windows Vista operating system has been used for a long time, you will find that the system disk space is getting more and more tight. What should I do at this time?
Solution
The default save location of offline file cache in VISTA system is : c:windowscsc” Change the default save location as follows:
1. Run the following command in the command prompt window of the administrator's permission:
REG ADD "HKLMSystemCurrentControlSetServicesCSCParameters" /v MigrationParameters /t REG_DWord /d 1 /f
2. Run the following command using the local administrator account: (Replace the partition letter in accordance with the actual situation)
c:windowssystem32migwizmigwiz.exe
3. In the Windows Easy Transfer Wizard, Select the following options in order:
(1) Click to start a new transfer.
(2) Click on my old computer.
(3) Click to use CD, DVD or other removable media.
(4) Click on the external hard drive or network location.
(5) Enter the location where you want Savedata.mig to save and click Next.
(6) Click on the advanced option.
(7) On the Select User Accounts, Files, and Settings page to transfer, do the following:
i. Deselect all selected check boxes.
ii. Under System and Program Settings (All Users), expand Windows Settings, expand Network and Internet, and select Offline Files.
iii. Repeat this for each user listed on this page.
(8) Click Next to start the transfer.
4, in the registry under the HKLMSystemCurrentControlSetServicesCSCParameters key to create a new string name called CacheLocation, and then set its value to the NT format name (NT format name) you want to cache the location. For example, if you want the cache to be saved in the d:csc directory, type ??d:csc.