يا جماعه قبل ما تمسحو شي، إعرفو ويش الي قاعدين تمسحوه

شوف ال Prefetch ويش وظيفته

Cleaning the Prefetch folder in Windows XP/Vista is a Myth and will reduce performance. The Prefetch folder is self cleaning at 128 entries by Windows. When the 128 limit is reached Windows will keep the 32 most used prefetch files. Cleaning the folder before this will cripple Windows load and all application load times. The Prefetch folder is not a cache. Prefetch files are NOT loaded at Windows startup and unused files do absolutely nothing but take up a ridiculously small amount of disk space. The folder is rarely over 5 MB. Prefetch (.pf) files are merely REFERENCED when an Application loads so Windows can optimally load the application to RAM. There is NO negative performance hit from Prefetching. All recommendations to clean the folder or tweak Windows Prefetching in ANY way are Myths and spread by those who do not
understand how Windows Prefetching works

يعني يا زيد ما غزيت راح تبطئ الجهاز اكثر في حالة تشغيل البرامج

اما بالنسبه لل dllcache فهو عباره عن مجلد يحتفظ بملفات النظام ويعملهن حمايه من النسخ المتكرر، وهذا الملفات تنشاء في عملية البوت واليكم الشرح بالإنجليزي من موقع مايكروسوفت

Windows File Protection (WFP) protects operating system files from being replaced by third-party programs or being accidentally deleted. When a file that is protected by this process is deleted or overwritten, WFP automatically replaces the file with the original version.

The %SystemRoot%\System32\DllCache folder by default caches all files on Windows 2000 Professional installations as long as there is enough disk space available. All protected files are cached in all Windows 2000 Server products.You can manually adjust the WFP cache size limit by using the Sfc.exe command-line utility. Type sfc /? to display usage and syntax information for Sfc.exe.

If your DLLCache is set to a certain size and you want to manually add files to the DllCache, you can do so but the files are not used until the next time you restart the computer.

WFP initializes and generates a list of files that are currently in the %SystemRoot%\System32\DLLCache folder each time the computer is booted. This file list is referenced whenever a protected file is modified or deleted. If the file is not on the current list that was created during the last reboot, WFP checks the original Windows installation source.

وانا من رأي حذف ال TMPfiles وال startup هيه انسب الطرق لتسريع الجهاز ولا تنسو الDefregmentation للهارد ديسك وال Disk clean utility

والسموحه من صاحب الموضوع