Hi, I use an i3-350M processor on my Toshiba Satallite L635. This is the intel link of my processor: https://ark.intel.com/content/www/tr/tr/ark/products/43529/intel-core-i3-350m-processor-3m-cache-2-2...
And my laptop's link: https://tr.dynabook.com/discontinued-products/satellite-l635-10j/
Recently I bought an i7-2820QM processor. This is the link of the processor: https://ark.intel.com/content/www/tr/tr/ark/products/52227/intel-core-i7-2820qm-processor-8m-cache-u...
Are they compatible? Can I change i3 to i7? Is it possible?
Likely not compatible.
Both of these processors support two different sockets (BGA and PGA). If your current processor is soldered to the motherboard (or on a daughter card) (BGA socket), then there is nothing you can do.
If PGA988 socketed, then you need to ask toshiba if their bios supports the i7-2820Q.
In my opinion, this type of upgrade on a laptop that is 10+ years old, is not worth the time and money (even if it is possible). Your graphics will be your biggest concern, as there is no Intel driver available (assuming you want to run Windows 10. You would have only the microsoft generic driver, which lacks features and performance.
Best to replace the laptop with something new(er).
Doc (not an Intel employee or contractor)