To format a computer means that all your data will be lost. Your operating system, programs, emails, drivers, pictures, everything! All of the updates on your programs will be gone, infarct the every entire program will be gone.
This drop in TSH is an attempt to return circulating thyroid hormone levels to normal. So, a test to measure the amount of TSH in your system will usually show lower than normal TSH when the thyroid is overactive. So, in general, LOWER TSH = OVERACTIVE THYROID / HYPERTHYROIDISM.
Higher levels of TSH push the thyroid to produce more hormone. Low TSH levels mean the thyroid is producing more than enough hormone. TSH levels can change a great deal with minor increases and decreases in T4. This is a very tightly regulated feedback process between the pituitary and the thyroid gland.