What is more effective for reviving performance - cleanup utilities or reinstalling the OS?

Solution 1:

A reinstall will assure a "clean slate" while a utility can help only to a limited extent.

Utilities generally are somewhat limited in what they clean up to avoid breaking applications or worse. They can be a good start, but a reinstall will usually be better

Solution 2:

The only way to keep good performances with a PC is to perform maintenance on regular basis such as:

• Checking S.M.A.R.T. data of your HD and if the result is "good": then Running CHKDSK

  Suggested tools: Piriform Speccy or SpeedFan (there's an online s.m.a.r.t. tool)

• Suppress unused softwares and UNutilities

• Run Windows disk cleaner or BleachBit or Ccleaner (but avoid Registry "cleanup")

• Defragment the volumes of the HD :Suggested tools: Windows defrag or Piriform Defraggler or Auslogic Defragmenter or Ms TechNet Sysinternals contig

• Update Windows and applications: Suggested tool: Secunia Software inspector

• You may also check for PC temperatures and clean dust accumulated in the box...

Finally take a look at MS FixIt Center: Fix Windows system performance problems on slow Windows computers

http://support.microsoft.com/mats/slow_windows_performance/en-us

Hope this help. Let us know. :)