stresa to murren

Train is the sensible way. You can look up times on the SBB (Swiss Railways) website: https://www.sbb.ch/en
No way 2 hours, this takes about 3½ hours, for example:

Stresa dep 09:21, Brig arr 10:16
Brig dep 10:48, Spiez arr 11:24
Spiez dep 11:33, Interlaken Ost arr 11:57
Interlaken Ost dep 12:05, Lauterbrunnen arr 12:25
Lauterbrunnen (Seilbahn) dep 12:38, Grütschalp arr 12:42
Grütschalp dep 12:44, Mürren BLM arr 12:58

For next week, SBB is currently selling tickets for: CHF 97. Tickets for mid-June are not yet available.
Don't let the large number of changes put you off, that is normal. And the road ends at Lauterbrunnen, the last leg muyt be by train.
Make sure you spell it Mürren, OR the alternative Muerren. Murren is wrong and the SBB site won't find it at that (mis-)spelling)

We did this route vice versa last fall: Lauterbrunnen to Domodossola to Stresa.

You would route from Stresa to Spiez and there is a direct train at 12:21 daily. That takes about 1.5 hours. Other options include one or two changes of train. I like to take direct trains as much as possible and avoid changes.

From Spiez, no reservations are required. You take the next train to Interlaken Ost, transfer to the train to Lauterbrunnen, then choose your route to Muerren. You can take the gondola from Lauterbrunnen to Grutschalp then the little train to Muerren, or the Post Bus to Stechelberg and gondola to Muerren. Might depend on where your lodging as to which to choose. The Spiez to Muerren legs should only take a bit over an hour.

No need for a private car. Cars can not go to Muerren anyway and must remain in the valley.

Thank you all for the help,I appreciate your assistance., train it will be....