Especially the Bolsheviks" return of Lenin from Switzerland with German support was an important event, bringing back his leader-skills and ideas. The fact that Germany also helped the Bolsheviks with some economic resources, eager as they were to get Russia out of the war, did neither weaken them. They were tightly organized with a clear goal of taking over power (April thesis) and govern Russia in the future. .
The power the Provisional Government was to have according to the army, were also weakened with the Soviet's "Order Number One" (14 of March) commanding all armies to establish a soldiers council in each regiment, were the soldiers were ordered only to deny orders conflicting with the Soviet's interests. The government could not anymore rely on the soldiers to obey their orders; it was the Petrograd Soviet who had the control of the army, and no longer them.
The Provisional Government did not obtain the support from the people due to many questions. The peasants had been demanding their right for own land for ages, and were waiting for land reforms to be putted into force, transferring land from e.g. kulaks to them. The government promised reforms to be brought in later, but the peasants were not willing to wait and even started to take the laws into their own hands and seize land for themselves. .
Russia was also impoverished after many years of war. The inflation was high, and there were serious economic problems affecting especially the lower classes. The fact that the February Revolution had it rising from a bread-queue, had not affected the results of the policy of the revolutionary government. The bread-prices were continuing to rise, the wages were still not being paid at the time, and there was shortage of fuel and raw materials. .
Defeat after defeat in the unpopular war made the economic situation even more difficult, and people were angry not being available to see any effort of all the fighting and loss of men.